Yes you were hitting a dismal peak TT and more importantly FT.
Keep in mind healthy estradiol levels are critical for bones, joints, ligaments and tendons.
Kyzatrex (oral TU) is short-acting due to the PK.
A fairly short peak T level, time to maximum concentration (Tmax) will be achieved 3-5 hrs post-dose then levels will decline fairly quick followed by much lower levels at trough.
You will get 2 daily peaks/troughs.
Look over the differences in Cmax achieved fasted vs low vs moderate vs high fat meal.
PK
View attachment 54805
View attachment 54806
View attachment 54807
View attachment 54808
Due to the solubilizers for TU used in the formulation the PK profiles have a profile that allows for increases in AUC without exceeding limits on Cmax.
Absorption
The KYZATREX® self-emulsifying drug delivery system is well absorbed from the gastrointestinal tract. Both testosterone undecanoate and the newly formed 5-alpha-dihydrotestosterone undecanoate are absorbed via the lymphatic system, circumventing first passage through the liver.
Following oral administration an important part of the active substance testosterone undecanoate is co-absorbed with the lipophilic solvent from the intestine into the lymphatic system, thus partially circumventing the first-pass inactivation by the liver. KYZATREX® must be taken with a normal meal or breakfast to ensure absorption.
KYZATREX® is expected to produce testosterone concentrations that approximate normal concentrations seen in healthy men.
When KYZATREX® was given with breakfast containing 16%, 33%, and 45% fat, the exposure (AUC 0- 24 hr) of testosterone was increased by 37%, 87%, and 94%, respectively, compared to when given under fasted conditions. The primary efficacy and safety study was conducted under fed conditions regardless of the type of meals and the primary efficacy endpoint of achieving testosterone C avg in normal testosterone range was met.
There was no effect on testosterone PK when KYZATREX® was administered with 20% alcohol along with a high-fat meal versus a high-fat meal alone.
View attachment 54809
Distribution:
Administration of radioactively labelled testosterone undecanoate (3H-TU) to men resulted in radioactivity in the lymph associated with unmetabolized testosterone undecanoate and 5-alpha- dihydrotestosterone undecanoate. Peak levels of radioactivity appeared in the lymph and plasma 2.5-5 hours after administration. Circulating testosterone is primarily (around 40%) bound in serum to sex hormone-binding globulin, 2% remains unbound (free), and the rest is loosely bound to albumin and other proteins.
Metabolism:
It is metabolized partly in the intestinal wall into 5-alpha-dihydrotestosterone undecanoate (DHTU) and in plasma and tissues TU is hydrolyzed to free testosterone and DHTU to DHT. Free testosterone is rapidly converted to 5-alpha-dihydrotestosterone, androstenedione and estradiol.
Elimination:
The highest concentration of radioactivity in urine was found 2 hours later. During the first 24 hours approximately 40% of the administered dose was found in urine and the total recovery of the dose in urine during the first week was 45-48%.