Just like nandrolone
PARTICIPATION NEEDED! Of those EM members that have taken nandrolone or are currently taking nandrolone alongside their TRT, we are conducting a small
ExcelMale study to help determine the effect that nandrolone has on Total Testosterone, E2, Prolactin, SHBG, free T, and DHT while taking TRT...
www.excelmale.com
Important note: Make sure you get testosterone total and free measured with mass spectrometry and free T with equilibrium dialysis and NOT using the common immunoassay. If you fail to do so, primo will show up as testosterone and your total T will be super high.
Discounted Labs sells that test:
The question comes up often in our community: What happens if you add Primobolan (metenolone enanthate) to a stable Testosterone Replacement Therapy (TRT) protocol? A member recently asked about the directional effects of adding 200mg of Primobolan per week to their existing 150mg per week TRT dose, wondering about the impact on everything from testosterone and estradiol to lipids and red blood cells.
This practice, sometimes called "TRT Plus," is a topic of great interest for men looking to optimize their protocol
beyond testosterone alone. While user anecdotes provide valuable insight, it's crucial to ground this discussion in verifiable data. Let's break down what the evidence and collective experience suggest.
The Critical First Step: Correct Lab Testing
Before diving into the effects, it's essential to address a major pitfall in monitoring a protocol that includes other androgens. As
ExcelMale founder
Nelson Vergel notes, standard immunoassay lab tests can't distinguish between testosterone and other similar steroid molecules.
If you use a standard test, Primobolan will likely be misread as testosterone, giving you a falsely elevated Total Testosterone reading. To get an accurate picture of what your testosterone levels actually are, you must use more advanced testing methods.
Important Note: When using any androgen in addition to testosterone, ensure your lab work for Total and Free Testosterone is done using Liquid Chromatography/Mass Spectrometry (LC/MS) and Equilibrium Dialysis. This ensures you are measuring
only testosterone.
Discounted Labs offers the correct panel for this purpose.
The Evidence Gap: A Lack of Clinical Studies
The first thing to understand is that there is a significant lack of formal clinical research on this specific combination. A search for peer-reviewed studies from 2022-2025 found no clinical trials specifically examining the effects of adding Metenolone Enanthate to a stable TRT regimen in men.pubmed.ncbi.nlm.nih.gov
Therefore, our understanding is built by combining anecdotal reports from experienced users with scientific principles and data from studies on individual compounds.
Potential Effects on Key Blood Markers
Based on user experiences and the pharmacology of metenolone, here's how adding it to your TRT might affect your bloodwork.
Estradiol (E2)
This is one of the most significant effects. Primobolan is a derivative of Dihydrotestosterone (DHT) and does not aromatize into estrogen. Furthermore, it's widely reported to have a notable anti-estrogenic effect, acting similarly to a mild Aromatase Inhibitor (AI).
One user on our forums reported that adding 100mg of Primobolan to their 125mg TRT dose "crashed my estrogen to single digits." This highlights Primobolan's potency in lowering E2. While this can be beneficial for men who struggle with high E2 on TRT, it also carries a significant risk of driving estrogen too low, leading to symptoms like joint pain, low libido, poor mood, and negative cardiovascular effects. Finding the right ratio of testosterone to Primobolan is key to keeping E2 in a healthy range.
Sex Hormone Binding Globulin (SHBG) and Free Testosterone
Primobolan is known to bind strongly to SHBG. This can lead to a significant reduction in circulating SHBG levels. One member noted his SHBG dropped from 19 nmol/L to 7 nmol/L. For context, a value of 7 is well below the standard reference range for most labs.specialtytesting.labcorp.comoptimaldx.com
By lowering SHBG, more testosterone becomes "unbound" or free. This means that even if your total testosterone dose remains the same, your Free Testosterone level may increase, which is often the primary goal for those adding compounds like Primobolan.
Lipids (Cholesterol)
This is a major area of concern. While there are no recent studies specifically on Primobolan's effect on cardiovascular markers, research on TRT alone shows it can decrease HDL-C (the "good" cholesterol) by around 8.7% over 12 months.pubmed.ncbi.nlm.gov Adding another anabolic compound, especially one that aggressively lowers estrogen, can worsen this effect. Estrogen plays a protective role in maintaining healthy cholesterol levels, so crashing your E2 with Primobolan can have a significant negative impact on your lipid profile. Regular monitoring is essential.
Hematocrit and Red Blood Cells (RBC)
All testosterone therapies are known to increase hematocrit and red blood cell count, which can thicken the blood and increase cardiovascular risk.pubmed.ncbi.nlm.gov Adding another anabolic steroid like Primobolan will likely compound this effect. If you choose to explore such a protocol, frequent monitoring of your hematocrit and regular blood donations may become necessary.
A Note on Legality and "TRT Plus"
Many users in our forums discuss the concept of "TRT Plus," where they use a foundational TRT dose and add other compounds like Primobolan, Masteron, or Nandrolone to achieve specific effects. Some users have reported that Primobolan and Proviron are legally available by prescription in countries like Spain.
This requires a critical correction.
Recent research into international regulations shows that Metenolone (Primobolan) is
not authorized for medical use in Spain. As of 2025, it is classified as a prohibited substance under Royal Decree 504/2025, and it cannot be legally prescribed or dispensed.boe.eselpais.com
However, Mesterolone (Proviron), another DHT derivative mentioned in the discussion,
is a prescription-only medication in Spain authorized for treating hypogonadism.cima.aemps.es
This highlights the importance of verifying information and understanding the legal and regulatory landscape, which can be complex and vary by country. While the "TRT Plus" approach is a reality for many, it exists in a legal gray area and is not supported by mainstream medical guidelines. The discussion around it should be framed within a context of harm reduction, acknowledging that while no international clinical guidelines exist for this practice, peer-led resources are emerging to promote safer use and health monitoring.aivl.org.auharmreductionjournal.biomedcentral.com
Summary and Final Thoughts
Adding Primobolan to a TRT protocol is an advanced strategy that comes with potential benefits and significant risks. Based on anecdotal evidence and pharmacological principles, here's a summary of the likely effects:
- Decreased Estradiol (E2): Acts as a mild AI, requiring careful dose management to avoid crashing E2.
- Decreased SHBG: Frees up more testosterone, potentially increasing Free T levels.
- Negative Impact on Lipids: Likely to lower HDL cholesterol, a risk compounded by lower E2 levels.
- Increased Hematocrit: Will likely add to the erythrocytosis effect of testosterone.
- Inaccurate Lab Results: Requires LC/MS testing to avoid falsely inflated testosterone readings.
Users often suggest starting with a 1:1 or 1.5:1 ratio of Testosterone to Primobolan (e.g., 150mg Test / 100mg Primo) and waiting at least 6-8 weeks for levels to stabilize before getting bloodwork. While many report positive effects on libido, mood, and body composition, these are not guaranteed and must be weighed against the health risks.
This exploration is for informational purposes only and is not medical advice. The lack of clinical data means anyone considering this path is moving into uncharted territory and should proceed with extreme caution, diligent monitoring, and ideally under the guidance of a knowledgeable healthcare provider.
For more information on how other compounds affect lab work, see our discussion here: Nandrolone (Deca Durabolin): Effect on Lab Tests -
Excel Male Health Forum.
but some guys use it constantly. In Spain it is legal. People love it. So much that as soon as is available it is sold out in all pharmacys. People run the pharmacys and buy it empty. It's crazy. Now we have to wait until February because Bayer.
