Testosterone Nicotinate
An obscure testosterone ester formed with nicotinic acid (niacin). Historically appearing in a handful of mid-20th-century preparations, it is essentially absent from modern medicine and sport. Its effects are those of testosterone; ester-specific human data are extremely sparse, so it is characterised largely by inference from the parent hormone.
01 Overview
Testosterone nicotinate esterifies testosterone at the 17-beta position with nicotinic acid. It was one of many ester variants explored in the era when manufacturers sought different release kinetics, but it never achieved wide clinical use and is rarely encountered today. As a result, dedicated pharmacokinetic, efficacy and safety studies are almost nonexistent.
Once the ester is cleaved the liberated hormone is ordinary testosterone, so the qualitative effect and side-effect picture matches testosterone. Ratings reflect the strong evidence base for the parent hormone combined with near-absent evidence for this specific ester, hence the low research score and observational/anecdotal grading for ester-specific claims.
02 Mechanism
Serum esterases hydrolyse the nicotinate ester to release free testosterone, which acts through the androgen receptor. Aromatisation to estradiol and 5-alpha reduction to DHT occur as with any testosterone preparation.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common (testosterone-equivalent) | 200–400 mg/wk | IM | Inferred from parent-hormone dosing; no robust ester-specific data. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Increased lean massAttributable to released testosterone acting on the androgen receptor. | dose-dependent | Clinical | |
| Increased strengthExpected from the parent hormone; no ester-specific trials. | Observational | ||
| Improved libidoTestosterone restoration typically improves libido. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| HPTA suppressionSuppresses endogenous gonadotropins and spermatogenesis. | Severe | Universal | Clinical | |
| Estrogenic effectsGynecomastia and water retention from aromatisation. | Moderate | Dose-dependent | Clinical | |
| Acne and oily skinAndrogenic stimulation of sebaceous glands. | Mild | Common | Clinical |