What is Trestolone Acetate?
Trestolone Acetate (MENT) is a synthetic anabolic androgen derived from the 19-nortestosterone family. Originally developed as a candidate for reversible male contraception, it has a short half-life of approximately one day, requiring daily injections.
MENT binds with high affinity to the androgen receptor and exhibits both strong anabolic and androgenic effects. In research contexts, it has been investigated for muscle growth, fat loss and endocrine changes.
This information is for research and educational purposes only. No medical advice.
Comparison
Related androgens
Targets according to the sources here or the entries in the TPD lexicon. Tap a card to open its entry.
Simplified: the same receptors do not mean the same effect. Unlike testosterone, MENT is not converted to DHT. 86
How it works
Trestolone works primarily through androgen receptor (AR) activation, leading to increased protein biosynthesis, enhanced nitrogen retention and stimulated erythropoietin production. Compared to testosterone, MENT exhibits approximately 10-fold higher anabolic potency.
- Strong androgenic signaling causes scalp and facial oiliness, possible acne
- Suppression of the hypothalamic-pituitary-gonadal (HPG) axis with suppressed endogenous testosterone production
- Aromatization to estradiol is possible, creating potential estrogenic side effects
- Relatively rapid clearance (approximately 1 day) requires daily injection
Where it acts
Where MENT acted in studies
Tap a point or a card. Grey = effect seen in trials.
- Hypothalamus and pituitary
LH -97%, FSH -95% with two or four implants, recovered after removal4
Observed in trials - Testes
At the highest level no detectable sperm in 8 of 12 men1
Observed in trials - Blood
Red blood cells, haematocrit and haemoglobin increased, reversible1
Observed in trials - Liver and blood lipids
Blood lipids moderately and transiently changed, liver values slightly1
Observed in trials - Bone
Lumbar spine bone density fell in hypogonadal men2
Observed in trials - Skeletal muscle
In rats ten times the effect of testosterone on muscle6
Observed in trials
Known targets8
Compound CHEMBL452329: three described targets, type of action on each card.
- Gene
- AR
- UniProt
- P10275
- ChEMBL
- CHEMBL1871
- Action
- Activates, about ten times as potent as testosterone and DHT (cell assay)
Application and dosing
Dosing
Dosing, titration and syringe
Loading the dosing information …
- Getting started and stepping up, drawn as a staircase
- Units on the U-100 syringe for every step
- How long one vial lasts
What the research shows
In a clinical trial on male contraception (von Eckardstein, 2003), subdermal MENT acetate implants suppressed sperm production in a dose-dependent way: with four implants, 8 of 12 men reached azoospermia. Side effects were the reversible changes typical of androgens, such as higher red blood cell counts and hematocrit.
- Studies on body composition suggest strong muscle building, but the evidence base for side effects at higher doses is limited
- Both estrogenic and androgenic effects occurred at all doses, making a balance difficult to achieve
- Seroconversion (antibody formation against the oil) was reported in some cases
- Return to baseline fertility occurred after cessation, but with variable timeline (weeks to months)
Study results
What the trials measured
Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.
Sperm production in the contraception trials15
Share of men per level, healthy volunteers with implants under the skin
Percentages calculated from the numbers in the abstract: no sperm 0 of 12, 2 of 11 and 8 of 12, below 3 million per ml 0 of 12, 4 of 11 and 9 of 12. In the second trial 8 of 10 with MENT and 13 of 16 with testosterone. There suppression under MENT did not last because the implants released less.
Hormone axis under implants4
Mean fall with two or four implants, 45 healthy men, 28 days
After the implants were removed all values fully returned. No serious adverse reactions, no consistent changes in blood chemistry and blood count.
Potency compared with testosterone (animals)67
Multiple of the effect of testosterone per organ, testosterone = 1
With testosterone 5-alpha reductase strengthens the effect in the prostate, MENT is not converted by it. Values as in the abstract, about 12-fold at the hormone axis in rats. Animal models, not directly transferable to humans.
Research status
Where the research stands
The registry lists one trial with MENT. The published implant trials (1999 to 2007) are not listed there. As of 26 Oct 2026. 10
- Preclinical Rats and monkeys: muscle more than prostate
- Phase 1 1 trial, 1 completed
- Phase 2 no registered trial
- Phase 3 no registered trial
- Approval not yet
Apart from 1 phase 1 trial there is no registered trial in phase 2 or later. 10
Side effects
Trestolone exhibits strong androgenic and estrogenic side effects due to its potency and partial aromatization.
- Androgenic: Acne, alopecia (male pattern hair loss in genetically predisposed), facial/scalp oiliness, irritability
- Estrogenic: Gynecomastia (breast tissue growth), fluid retention, elevated blood pressure
- HPG axis suppression: Testosterone decline, testicular atrophy possible - post-cycle therapy typical
- Cardiovascular: Potential blood pressure elevation, lipid profile changes
- Hepatic: Minimal for oil form; liver enzyme elevations not typical
- Psychiatric: Mood swings, aggression (in rare cases)
Storage
Trestolone Acetate oil must be stored at room temperature, protected from light. A refrigerator is not required and may actually promote crystallization.
- Temperature: 15-25°C ideal
- Light: Store in dark (original vials or amber glass)
- Moisture: Keep dry
- Shelf life: At least 2-3 years stable with proper storage
- After opening: Needle punctures increase infection risk - use sterile technique
