What is the Optimum TRT Dose for Muscle Growth? : Nelson Vergel Reviews the Data

Landmark Study Reveals How Different Testosterone Doses Affect Muscle, Fat, and Health Markers in Young Men

A deep dive into one of the most influential studies on testosterone dosing reveals key takeaways for anyone interested in hormone optimization—a topic of persistent debate in men's health communities and clinics alike.

Background and Study Design

In 2001, a seminal paper was published in the American Journal of Physiology, Endocrinology and Metabolism. Dr. Shalender Bhasin and colleagues—considered among the top experts on androgens—sought to answer a fundamental question: What are the effects of different weekly testosterone doses on strength, body composition, and key health markers in healthy young men?

The research team recruited approximately 65 men, average age 25, all generally healthy and fit. Each participant’s natural testosterone production was first suppressed with a medication, then replaced in varying increments—25, 50, 125, 300, or 600 mg per week of testosterone cypionate injections for 20 consecutive weeks.

Critically, participants were instructed not to exercise during the study, and their caloric and protein intake was monitored to ensure changes resulted solely from hormone adjustments[1].

Main Findings

Serum Testosterone Levels

25 mg/week: Levels dropped well below baseline; insufficient for replacement.​

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50 mg/week: Some increase, but still suboptimal.​

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125 mg/week: Returned testosterone to baseline (pre-suppression) levels for these young men.​

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300–600 mg/week: Produced supraphysiological levels—common in bodybuilding circles[1].​

Body Composition

Lean Mass (Fat-Free Mass): Significant increases began at 100–125 mg/week and continued at higher doses. These gains were recorded despite no exercise, confirming testosterone’s powerful anabolic potential.​

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Fat Mass: Doses of 100–125 mg/week and above led to reductions in fat mass. Lower doses (25–50 mg/week) paradoxically increased fat mass, suggesting underdosing may be counterproductive[1].​

Muscle Volume and Strength

Thigh and quadriceps volume, measured by MRI, significantly increased at 125 mg/week and higher. Leg press strength and power only improved at high doses (300–600 mg/week)[1].

IGF-1 and Growth Factors

Doses below 125 mg/week did not increase IGF-1. Only high, bodybuilding-type doses (300–600 mg/week) led to statistically significant increases—raising interesting questions about synergy with exercise, which was not tested in this trial[1].

Sexual Function and Libido

Overall, no significant enhancements in sexual activity or libido were noted, regardless of dose. Minor fluctuations occurred, but neither sexual frequency nor desire reached statistical significance. It’s worth noting subjects first received a testosterone blocker before hormone administration, potentially influencing these endpoints[1].

Blood Markers and Safety

Hematocrit and Hemoglobin: Both rose substantially with higher doses, reflecting increased red blood cell mass—a potential cardiovascular risk at extreme levels.​

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HDL Cholesterol: “Good” cholesterol (HDL) decreased in a dose-dependent manner, also raising potential long-term cardiovascular concerns.​

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Prostate-Specific Antigen (PSA): No major changes were observed, likely due to participants’ young age[1].​

Key Practical Insights

• 100–125 mg/week appears optimal for returning serum testosterone and body composition to healthy levels in young adults after suppression.
• Underdosing (25–50 mg/week) is not effective and may increase fat mass.
• Bodybuilding-level doses (300–600 mg/week) yield dramatic increases in testosterone, IGF-1, lean mass, and strength, but at the expense of cardiovascular risk markers like elevated hematocrit and reduced HDL.
• Sexual and cognitive function do not significantly increase simply by raising testosterone above baseline, at least in healthy young men[1].

Study Limitations and Final Thoughts

This remains one of the most comprehensive testosterone dose-response studies to date, especially given its use of direct hormone suppression followed by graded repletion and rigorous controls on diet and exercise. However, its sample was limited to healthy, non-obese men in their 20s who did not work out during the protocol. Results may differ in older or overweight men, or those actively engaged in resistance training.

Studies of this rigor and scope are rare—and, given regulatory and ethical barriers, may not be repeated soon. For clinicians and men considering testosterone therapy, this data offers a rare, data-driven roadmap for setting rational expectations and weighing benefits against potential risks[1].

More details: Responses of different doses of testosterone injections on body composition, strength, etc. - Excel Male TRT Forum

 

Briefing Document: Testosterone Dose-Response Relationships in Healthy Young Men​

Source: Bhasin, S., Woodhouse, L., Casaburi, R., et al. (2001). "Testosterone dose-response relationships in healthy young men." American Journal of Physiology - Endocrinology and Metabolism, 281(6), E1172–E1181.

Date of Publication: December 2001

Lead Author/Institution: Shalender Bhasin, Division of Endocrinology, Metabolism, and Molecular Medicine, Charles R. Drew University of Medicine and Science, Los Angeles.

NOTE: No exercise was included in this study.

Executive Summary​

This study investigated the dose-dependent effects of testosterone on various physiological processes in healthy young men. By suppressing endogenous testosterone and administering graded doses of testosterone enanthate, researchers established different circulating testosterone levels ranging from subphysiological to supraphysiological. The study found a clear dose- and concentration-dependent relationship between testosterone and changes in fat-free mass, muscle size, strength, power, fat mass, hemoglobin, and IGF-I levels. Conversely, sexual function, visual-spatial cognition, mood, and prostate-specific antigen (PSA) levels did not show significant dose-dependent changes, with some of these functions being maintained even at lower testosterone doses. This indicates that "different androgen-dependent processes have different testosterone dose-response relationships." The study also notes that doses leading to significant muscle gains were associated with reductions in plasma HDL cholesterol, highlighting a potential trade-off between anabolic effects and cardiovascular risk.

Key Findings and Main Themes​

1. Dose-Dependent Effects on Body Composition and Muscle Performance:

• Fat-Free Mass (FFM) and Muscle Size: FFM "increased dose dependently in men receiving 125, 300, or 600 mg of testosterone weekly (change ±3.4, 5.2, and 7.9 kg, respectively)." Changes in FFM were "highly dependent on testosterone dose (P = 0.0001) and correlated with log testosterone concentrations (r = 0.73, P = 0.0001)." Similar dose-dependent increases were observed in thigh muscle and quadriceps muscle volumes. The relationship for FFM and muscle size conformed to a "single log-linear dose-response curve," rather than two separate curves for hypogonadal and supraphysiological ranges.
• Muscle Strength and Power: Leg press strength and leg power also increased in a dose-dependent manner, particularly at the 300-mg and 600-mg doses. Changes in leg press strength correlated with log testosterone levels (r = 0.48, P = 0.0005) and changes in muscle volume and FFM.
• Fat Mass: Fat mass "increased significantly in men receiving the 25- and 50-mg doses but did not change in men receiving the higher doses of testosterone." There was an "inverse correlation between change in fat mass... and log testosterone concentrations (r = -0.60, P = 0.0001)."

1. Differential Dose-Response Relationships for Various Androgen-Dependent Processes:

• Sexual Function, Cognition, and Mood: "Sexual function, visual-spatial cognition and mood, and PSA levels did not change significantly at any dose." This implies that "serum testosterone concentrations at the lower end of male range can maintain some aspects of sexual function."
• Prostate-Specific Antigen (PSA): PSA levels "did not change significantly at any dose," suggesting that even lower doses of testosterone were sufficient to maintain PSA within normal ranges in these eugonadal men. The study did not measure prostate volume.
• Hemoglobin: Hemoglobin levels "decreased significantly in men receiving the 50-mg dose but increased at the 600-mg dose; the changes in hemoglobin were positively correlated with testosterone concentrations (r = 0.66, P = 0.0001)."
• Plasma Lipids (HDL Cholesterol): Changes in plasma HDL cholesterol were "negatively dependent on testosterone dose (P = 0.0049) and correlated with testosterone concentrations (r = -0.40, P = 0.0054)." This is a significant finding regarding potential cardiovascular risk.
• Insulin-like Growth Factor I (IGF-I): IGF-I concentrations "increased dose dependently at the 300- and 600-mg doses (correlation between log testosterone level and change in IGF-I = 0.55, P = 0.0001)."

1. Study Design and Methodology:

• Participants: 61 healthy eugonadal men, aged 18-35 years, with prior weight-lifting experience. 54 completed the study.
• Intervention: Participants received monthly injections of a GnRH agonist to suppress endogenous testosterone, plus weekly intramuscular injections of testosterone enanthate at doses of 25, 50, 125, 300, or 600 mg for 20 weeks.
• Standardization: Energy and protein intakes were standardized, and participants were instructed "not to undertake strength training or moderate-to-heavy endurance exercise during the study" to isolate the effects of testosterone.
• Outcome Measures: Body composition (underwater weighing, DEXA), muscle size (MRI), strength (leg press 1-RM), power (Nottingham leg extensor power rig), sexual function (daily logs), cognitive function (computerized checkerboard test), mood scales, blood counts, plasma lipids, PSA, and various hormone levels.
• Testosterone Levels Achieved: Mean nadir testosterone concentrations ranged from 253 ng/dl (25 mg dose) to 2,370 ng/dl (600 mg dose), demonstrating successful manipulation of testosterone levels across a wide range.

1. Implications and Future Directions:

• The study clarifies that "different androgen-dependent processes have different testosterone dose-response relationships." This information is crucial for optimizing testosterone replacement regimens for hypogonadal men and for potential uses in sarcopenia.
• A significant trade-off was observed: "Testosterone doses associated with significant gains in fat-free mass, muscle size, and strength were associated with significant reductions in plasma HDL concentrations."
• The authors highlight the need for "further studies... to determine whether clinically significant anabolic effects of testosterone can be achieved without adversely affecting cardiovascular risk."
• The findings support the development of "Selective androgen receptor modulators (SARMs) that preferentially augment muscle mass and strength, but only minimally affect prostate and cardiovascular risk factors."
• The study acknowledges limitations, including the measurement of nadir testosterone levels (fluctuations exist with weekly injections) and the lack of prostate volume measurements. It also questions whether responsiveness to testosterone is attenuated in older men and how other factors like nutritional status and exercise modulate the dose-response.

Critical Considerations​

• Generalizability: While rigorous, the study was conducted on healthy young men with prior weight-lifting experience. The findings may not directly apply to older men, sedentary individuals, or those with chronic illnesses, where testosterone dose-response relationships might differ.
• Long-term Effects: The study duration was 20 weeks. The "long-term effects of androgen administration on the prostate, cardiovascular risk, and behavior are unknown."
• Testosterone Delivery Method: Weekly injections lead to fluctuations in testosterone levels. The authors suggest that "sustained testosterone delivery by a patch or gel might reveal different dose-response relationships, particularly with respect to hemoglobin and HDL cholesterol."
• Individual Variability: Despite clear dose-dependent mean changes, "there was considerable heterogeneity in response to testosterone administration within each group," suggesting that individual factors (e.g., genetics, metabolism) play a role.

 

Nelson are you still progressing in the gym, you are jacked! I'm training 5 or 6 days per week and its tough.. going to failure and 6 to 16 sets per muscle per week.

 

FAQs on Testosterone Dosing and Effects​

What was the purpose and methodology of the 2001 study on testosterone dosing?​

The study, led by Dr. Bhasin and published in the American Journal of Physiology, aimed to determine the effects of different testosterone doses on young, healthy men. Researchers blocked the natural testosterone production of 65 participants (average age 25) and then administered weekly injections of testosterone cypionate at doses of 25 mg, 50 mg, 125 mg, 300 mg, and 600 mg for 20 weeks. Participants were specifically asked not to work out, and their food intake was monitored to ensure changes weren't due to diet. Various metrics were measured, including hormone levels (total and free testosterone, LH, SHBG, IGF-1), body composition (fat-free mass, fat mass), muscle volume, strength, sexual function, and blood work (hemoglobin, hematocrit, PSA, HDL).

How did different testosterone doses affect total and free testosterone levels?​

As expected, both total and free testosterone levels increased with higher doses of injected testosterone. Interestingly, the 25 mg per week dose actually led to a decrease in total testosterone from baseline (e.g., from ~593 to 253 ng/dL), indicating it was insufficient to replace natural production. A dose of 125 mg per week brought total testosterone back to approximate baseline levels. Doses of 300 mg and 600 mg per week resulted in significantly elevated total testosterone levels (1300-2300 ng/dL), far exceeding typical physiological ranges.

What impact did testosterone dosing have on body composition and muscle growth, even without exercise?​

The study showed significant improvements in fat-free mass (lean mass) and decreases in fat mass with increasing testosterone doses. Doses of 125 mg per week and above led to clear positive changes. Notably, the lower doses (25 mg and 50 mg) actually resulted in an increase in fat mass, suggesting that underdosing can be detrimental. MRI measurements of thigh and quad muscle volume also showed significant increases starting at the 125 mg dose, even though participants were not exercising. This highlights the powerful anabolic effects of testosterone itself.

Did different testosterone doses significantly impact sexual function and desire?​

The study's findings on sexual activity and desire were not statistically significant across the different doses. While some individual variations were observed, there wasn't a clear or strong correlation between testosterone dose and changes in sexual activity scores or intensity of sexual desire (libido). The small sample size per group (12 participants) might have contributed to this lack of statistical significance. It's important to remember that these were young men whose natural testosterone was blocked before treatment, which could also influence the observed sexual responses.

What were the effects of testosterone dosing on IGF-1 and strength markers?​

IGF-1 (insulin-like growth factor 1), a metabolite of growth hormone, did not show statistically significant changes at lower testosterone doses (25 mg, 50 mg, 125 mg). However, at higher, "bodybuilding" doses of 300 mg and 600 mg per week, a statistically significant increase in IGF-1 was observed. Regarding strength, leg press strength and leg power significantly increased at the 300 mg and 600 mg doses, even though the participants were explicitly instructed not to work out. This indicates that higher testosterone levels alone can improve strength.

What were the notable changes observed in blood markers, such as hemoglobin, hematocrit, and HDL cholesterol?​

Higher testosterone doses led to increases in hemoglobin and red blood cell count (hematocrit), which is a known effect of testosterone. The study notes ongoing debate about the "magic highest number" for hematocrit before cardiovascular issues arise. Critically, the "good" cholesterol, HDL, significantly decreased as the testosterone dose increased. The presenter highlights that the rise in hemoglobin/hematocrit and the decrease in HDL are "prices to pay" for higher doses, as they indicate an increased cardiovascular risk. PSA (Prostate-Specific Antigen) showed only minor, non-significant changes.

What is considered a "replacement" dose versus a "bodybuilding" dose based on this study?​

Based on this study, a weekly testosterone cypionate dose of approximately 100-125 mg was found to be effective in bringing total testosterone levels back to baseline in young men whose natural production was suppressed. This range could be considered a "replacement" or physiological dose. Doses of 300 mg and 600 mg per week are characterized as "bodybuilding" doses, as they significantly elevated total testosterone, IGF-1, muscle mass, and strength, beyond typical physiological replacement levels.

What are the main takeaways or limitations of this study?​

This study provides valuable insights into the dose-dependent effects of testosterone, particularly its anabolic effects on muscle and fat mass even without exercise. It highlights that underdosing (25-50 mg/week) can be counterproductive, while higher doses significantly improve strength and body composition but come with potential risks like decreased HDL and increased hematocrit. The study's limitations include its focus on young, healthy men (results may differ for older or less healthy populations), the relatively small sample size per dose group, and the unique methodology of blocking natural testosterone before administering exogenous doses. The presenter emphasizes that such a comprehensive study, especially with high doses, is unlikely to be replicated today due to ethical and logistical considerations.

 

Did different testosterone doses significantly impact sexual function and desire?​

The study's findings on sexual activity and desire were not statistically significant across the different doses. While some individual variations were observed, there wasn't a clear or strong correlation between testosterone dose and changes in sexual activity scores or intensity of sexual desire (libido). The small sample size per group (12 participants) might have contributed to this lack of statistical significance. It's important to remember that these were young men whose natural testosterone was blocked before treatment, which could also influence the observed sexual responses.

The fact that none of the men showed increase in libido is interesting. Then again, these were guys were young so probably had normal levels of libido to begin with.

 

The fact that none of the men showed increase in libido is interesting. Then again, these were guys were young so probably had normal levels of libido to begin with.

Good point.

 

What is then the optimal TRT Dose for muscle growth for older adults? 125mg?

 

Testosterone Dose-Response Effects on Body Composition in Young and Older Men​

A Comparative Analysis: Young vs. Older Men​

Executive Summary​

The landmark studies by Shalender Bhasin and colleagues provide the most definitive evidence on testosterone dose-response relationships. Their research demonstrated that older men (60-75 years) are as responsive as young men (18-35 years) to testosterone's anabolic effects on skeletal muscle, though with important differences in pharmacokinetics and adverse event profiles. Fat-free mass and strength gains follow a single linear dose-response curve across both age groups, challenging the assumption of age-related androgen resistance.

Key Study Design​

The definitive research comes from two complementary trials published in the American Journal of Physiology (2001) and Journal of Clinical Endocrinology & Metabolism (2005). The design was rigorous:
Participants: 61 young men (18-35 years) and 60 older men (60-75 years), all eugonadal at baseline
Protocol: 20-week treatment with GnRH agonist (to suppress endogenous T) plus weekly testosterone enanthate
Doses: 25, 50, 125, 300, or 600 mg weekly
Controls: Standardized energy (150 kJ/kg/d) and protein (1.3 g/kg/d) intake; no resistance training
Measurements: DEXA, underwater weighing, 1-RM leg press, MRI muscle volume

Resulting Testosterone Concentrations​

The graded doses produced a wide spectrum of testosterone levels:

Dose (mg/wk)	Young T (ng/dL)	Older T (ng/dL)	Classification	Notes
25	253	176	Severely low	Hypogonadal range
50	306	274	Low-normal	Borderline
125	542	852	High-normal	Optimal trade-off
300	1,345	1,784	Supraphysiologic	~3x upper limit
600	2,370	3,286	Very high	~5-6x upper limit

Key finding: Older men achieved significantly higher testosterone levels than young men at the same doses (P < 0.0001), indicating reduced testosterone clearance with aging.

Fat-Free Mass Changes​

FFM changes were highly correlated with testosterone dose (P = 0.0001) and showed a linear relationship with log testosterone concentrations (r = 0.73 in young men, r = 0.77 in older men):

Dose (mg/wk)	Young FFM (kg)	Older FFM (kg)	Significance
25	-1.0	-0.3	Loss at hypogonadal T
50	+1.0	+1.7	Modest gain
125	+3.4	+4.2	Best trade-off dose
300	+5.2	+5.6	Supraphysiologic
600	+7.9	+7.3	Maximum tested

Critical finding: After adjusting for testosterone levels, there was no significant difference in FFM response between young and older men (age effect P = 0.54). The dose-response curves were essentially parallel.

Fat Mass Changes​

Fat mass changes correlated inversely with testosterone dose (r = -0.54, P < 0.001). However, this was the ONE parameter showing a significant age difference (P < 0.0001):

Dose (mg/wk)	Young Fat (kg)	Older Fat (kg)	Age Difference
25	+2.6	+0.1	P < 0.0001
50	+1.5	-0.9	P < 0.0001
125	-0.5	-1.5	NS
300	-1.6	-2.2	NS
600	-2.9	-3.0	NS

Key observation: Young men at subphysiologic testosterone levels (25-50 mg doses) gained significant fat mass, while older men did not show the same fat gain pattern. At higher doses (125+ mg), both groups lost fat similarly. This may reflect differential metabolic responses to testosterone deficiency by age.

Muscle Strength Changes​

Leg press strength (1-RM) increased dose-dependently and correlated with testosterone levels (r = 0.48-0.51, P < 0.001):

Dose (mg/wk)	Young Strength (kg)	Older Strength (kg)	Notes
25	-8	+1	No gain
50	+15	+12	Modest
125	+9	+28	Significant gain
300	+35	+52	Large gain
600	+35	+30	Plateau effect

Notable finding: Strength gains did not show a significant age effect (P = 0.29). Older men at the 125 mg and 300 mg doses showed particularly robust strength gains (28-52 kg), demonstrating that skeletal muscle in older men remains highly responsive to testosterone.
Additional findings from Storer et al. (2003): Testosterone dose-dependently increased maximal voluntary strength and leg power, but did not affect muscle fatigability or specific tension (force per unit muscle area). This suggests testosterone increases strength primarily by increasing muscle size rather than improving intrinsic muscle quality.

Cellular and Molecular Mechanisms​

1. Satellite Cell Activation and Myonuclear Accretion​

Testosterone-induced muscle hypertrophy is associated with dose-dependent increases in satellite cell number (Sinha-Hikim et al., 2003). These muscle stem cells, located between the sarcolemma and basal lamina, express androgen receptors predominantly. Key findings: Satellite cell number increases with testosterone; these cells fuse with existing muscle fibers, increasing myonuclear number; the correlation between fiber area and myonuclei number is strong (r = 0.86, P < 0.0001); and type II muscle fibers show greater responsiveness than type I fibers.

2. Protein Synthesis Enhancement​

Testosterone replacement in hypogonadal men increases fractional muscle protein synthesis rate by approximately 56% (P = 0.015) (Brodsky et al., 1996). The primary mechanism during the first month of therapy is increased protein synthesis, with reduced protein breakdown becoming more prominent with continued treatment. Ferrando et al. demonstrated that testosterone increases the reutilization of intracellular amino acids from protein breakdown for new protein synthesis.

3. Mesenchymal Stem Cell Commitment​

Testosterone promotes the commitment of pluripotent mesenchymal precursor cells into myogenic lineage while inhibiting adipogenic differentiation (Bhasin et al., 2003). This dual effect helps explain the reciprocal changes in muscle and fat mass observed with testosterone therapy. C3H 10T1/2 pluripotent cell studies confirm androgens stimulate myogenic differentiation through androgen receptor-mediated pathways.

4. Androgen Receptor Dynamics​

Androgen receptors are expressed predominantly in satellite cells and myonuclei. Testosterone treatment upregulates AR expression in skeletal muscle, creating a positive feedback mechanism. Importantly, AR expression may vary between muscles (e.g., trapezius vs. vastus lateralis), potentially explaining differential responses in various muscle groups.

5. IGF-1 Upregulation​

Testosterone administration increases intramuscular IGF-1 mRNA and protein expression. This local growth factor amplifies the anabolic signal and may mediate some of testosterone's effects on protein synthesis. Studies making men hypogonadal with GnRH analogs showed decreased muscle IGF-1 mRNA, which was restored with testosterone replacement.

Safety Profile: Age-Related Differences​

The safety profile differed significantly between young and older men, particularly at supraphysiologic doses:

Hematologic Effects​

Dose-dependent increases in hemoglobin and hematocrit were the most significant adverse finding. Older men had significantly greater hematocrit increments than young men (P < 0.0001). Hematocrit >54% occurred in: 0 young men across all doses; 1 older man at 125 mg; 3 older men at 300 mg; 2 older men at 600 mg. This was the most common dose-limiting adverse event and led to discontinuation of the 600 mg arm in older men.

Prostate-Related Events​

PSA levels did not change significantly at any dose in either age group. However, two older men were diagnosed with prostate cancer during the study (one at 300 mg, one at 50 mg). Baseline PSA was higher in older men. The authors note this may reflect detection bias from intensive monitoring rather than testosterone-induced cancer development.

Other Adverse Events​

Older men: 147 adverse events, 12 serious adverse events (including leg edema with shortness of breath, urinary retention). Young men: 55 adverse events, no serious adverse events. Young men had higher rates of acne, while older men experienced more leg edema (particularly at 300-600 mg doses).

Lipid Effects​

HDL cholesterol decreased dose-dependently, with significant decreases only at the 600 mg dose (-12 mg/dL in older men). LDL cholesterol and triglycerides did not change significantly. No significant age effect on lipid changes.

Clinical Implications and Optimal Dosing​

The 125 mg Weekly "Sweet Spot"​

The 125 mg weekly dose emerged as the optimal trade-off between efficacy and safety: Achieved high-normal testosterone levels (~542-852 ng/dL); Produced significant FFM gains (+3.4 to +4.2 kg); Generated meaningful strength improvements (+9 to +28 kg leg press); Led to modest fat loss (~0.5 to 1.5 kg); Had no serious adverse events in either age group; Showed minimal HDL suppression.

Age-Specific Dosing Considerations​

Critical pharmacokinetic finding: Older men achieve higher testosterone levels than young men at the same doses due to reduced clearance. This has two practical implications: Older men may require lower doses to achieve target testosterone levels; Safety monitoring (especially hematocrit) must be more stringent in older men.

Key Takeaways for Clinical Practice​

1. Age is not a barrier to anabolic response: Older men respond just as well as young men in terms of muscle mass and strength gains per unit testosterone.
2. The dose-response is linear: There is no evidence of androgen receptor saturation or age-related resistance within the physiologic-to-supraphysiologic range.
3. Sexual function thresholds differ from muscle thresholds: Sexual function is maintained at lower testosterone concentrations (~250-300 ng/dL) than those required for optimal muscle accretion (500+ ng/dL).
4. The 125 mg dose provides the best risk-benefit profile: Substantial gains in FFM and strength without the serious adverse events seen at 300-600 mg doses.
5. Exercise amplifies effects: The NEJM study (Bhasin 1996) showed testosterone + exercise produces greater gains (6.1 kg FFM) than testosterone alone (3.2 kg) or exercise alone (1.9 kg).

Key References​

1. Bhasin S, et al. Testosterone dose-response relationships in healthy young men. Am J Physiol Endocrinol Metab. 2001;281(6):E1172-E1181. [PubMed]
2. Bhasin S, et al. Older men are as responsive as young men to the anabolic effects of graded doses of testosterone on skeletal muscle. J Clin Endocrinol Metab. 2005;90(2):678-688. [PubMed]
3. Bhasin S, et al. The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men. N Engl J Med. 1996;335(1):1-7. [PubMed]
4. Sinha-Hikim I, et al. Testosterone-induced increase in muscle size in healthy young men is associated with an increase in satellite cell number. Am J Physiol Endocrinol Metab. 2003;285(1):E197-E205. [PubMed]
5. Brodsky IG, et al. Effects of testosterone replacement on muscle mass and muscle protein synthesis in hypogonadal men. J Clin Endocrinol Metab. 1996;81(10):3469-3475. [PubMed]
6. Storer TW, et al. Testosterone dose-dependently increases maximal voluntary strength and leg power. J Clin Endocrinol Metab. 2003;88(4):1478-1485. [PubMed]
7. Ferrando AA, et al. Testosterone administration to older men improves muscle function: molecular and physiological mechanisms. Am J Physiol Endocrinol Metab. 2002;282(3):E601-E607. [PubMed]
8. Sinha-Hikim I, et al. Androgen receptor in human skeletal muscle and cultured muscle satellite cells: up-regulation by androgen treatment. J Clin Endocrinol Metab. 2004;89(10):5245-5255. [PubMed]

 

Great studies @Nelson Vergel. I know everyone is different and for some people 125/week may be too much, but I often promote 100-125/week as a good starting dose and am surprised how much pushback I get from some of the posters here. Lots of studies/evidence show that somewhere around the 120/week range provides a lot of the good benefits while still minimizing the likelihood of unwanted side effects.

 

I know everyone is different and for some people 125/week may be too much, but I often promote 100-125/week as a good starting dose and am surprised how much pushback I get from some of the posters here.

It's a natural response from most men using TRT. There is no way to convince them that more is not always better in the long run. It's like trying to convince them that estradiol is important for men. Or that high hematocrit caused by TRT is not the same as higher hematocrit because of higher altitudes. Etc, Etc.

 

It's a natural response from most men using TRT. There is no way to convince them that more is not always better in the long run. It's like trying to convince them that estradiol is important for men. Or that high hematocrit caused by TRT is not the same as higher hematocrit because of higher altitudes. Etc, Etc.

Yeah, I think these views just get kind of ingrained and after that most people are hesitant to change. In my post above I was actually referring to posters here who say 120/week is too high. I had an extensive discussion with Cataceous and shared tons of evidence similar to the things you’ve posted in this study and yet he still slams me any time it’s mentioned that 120/week could be considered a great dose for most people. Not to single him out though because there are others, and to an extent we’re all hesitant to change our minds on things, it’s just that some are more so than others. Funnily enough, on here I get pushback for saying 120/week is a great starting point by people saying it’s too high, and in other places you get slammed by people who say it’s too low lol. Meanwhile as we see in this thread there is plenty of evidence suggesting it’s a good balancing point between increased benefits with minimal negative sides.

I think an important thing is to accept nuance and not speak in absolutes, and to also put our egos aside and be willing to adjust views as evidence suggests. As an example of the nuance perspective, when people actually started recognizing the value of E2 plenty of people went overboard and suggesting that E2 never causes unwanted side effects or even that bloodwork doesn’t tell us anything at all with regard to what’s going on in our body when it comes to E2. Now that mindset is locked in for plenty of people, despite the fact that plenty of studies suggest that serum E2 levels can give us a good idea of what’s going on in the body.

We’re all learning on this front as we go, and getting closer to the truth should be a higher goal than being right.