Fadogia Agrestis
Also known as: Fadogia, Fadogia agrestis stem extract
Popular on the strength of a single rat study — which also found testicular damage at higher doses and longer duration. There are no human trials at all, and that combination is the whole point of this page.
Substance family
Vitamins, minerals, amino acids and enzymes. The recurring pattern: correcting an actual deficiency helps, supplementing beyond a normal level generally does not.
Effects on
Which outcomes this substance acts on — descriptive, not a recommendation.
Strain profile
Where this substance is most likely to hit — a rough orientation, individually dependent on dose, duration and predisposition.
Dosing & protocols by goal
Rough orientation ranges as reported in harm-reduction literature — not an individual treatment plan. Doses are individual and open-ended; frequency depends on the ester or half-life.
Commonly used amounts
Not recommendedDose
Commonly 600 mg / day, cycled
Frequency
1× / day
Cycle length
Often cycled 8 weeks on, 4 off
Listed because it is what circulates, not as a recommendation. There is no human dosing data — the figure derives from bodybuilding practice, not from a trial.
Side effect & countermeasure
Typical problems and what you can do to reduce harm — at a glance. Does not replace medical monitoring.
Problem
Taken long-term, continuously
Countermeasure
The one animal study that established its reputation also found testicular toxicity with longer administration at higher doses. If it is used at all, short and cycled is the only defensible approach.
Problem
Used as a testosterone booster instead of testing
Countermeasure
Test total and free testosteronefree testosteroneThe fraction of testosterone not bound to a transport protein — the part that actually works., LH and FSH. If the level is genuinely low, that has causes worth identifying — and a plant extract with no human trials is not the answer to any of them.
Overview
Fadogia Agrestis became popular through podcasts and supplement marketing, on the strength of a body of evidence that consists of animal work — principally a 2005 rat study.
That study is worth reading carefully, because it is quoted for one of its findings and almost never for the other.
What the study actually found
Rats given Fadogia agrestis stem extract showed increased testosterone. That is the finding everyone cites.
The same line of work also documented testicular toxicity — damage to the tissue that produces testosterone — with higher doses and longer administration. That finding is cited far less often, and it is the more important one for anyone considering taking it daily for months.
There are no human trials. Not small ones, not poor ones. None. Everything about human dosing, safety and duration is extrapolation from rodents.
Why that matters more here than usual
Consider what someone typically takes this for: raising testosterone, often after a cycle, often precisely when the testes are already suppressed and recovering.
A compound with animal evidence of testicular damage is a poor choice at exactly that moment. Not because the risk is established in humans — it is not — but because nothing about the risk is established in humans either way, and the tissue in question is the one you are trying to recover.
Compared with Tongkat Ali
The two are marketed together and sold in the same combination products, which obscures a real difference: Tongkat Ali has human trials and a mild, documented effect. Fadogia has neither.
If the goal is a natural testosterone supplement with something behind it, those are not equivalent options.
Side Effects & Risks
- Testicular toxicity in animal studies at higher doses and longer duration
- Reports of raised liver values in users, without systematic study
- No human safety data of any kind
- No established dose, duration or upper limit
- Not authorised as a novel food in the EU, which reflects exactly this absence of evaluation
Blood Work & Monitoring
- Total and free testosterone, LH, FSH — before and after, if it is used at all
- ALT, AST — given the liver reports, and because nothing else is known
Harm-Reduction Notes
- The honest position: the evidence base does not support taking this, and the one study behind its reputation contains a finding that argues against it
- If used anyway, short and cycled rather than continuous, and not while recovering from suppression
- Combination products often hide it behind a proprietary blend — read what is in them
- If low testosterone is the actual problem, that is a blood test and a cause worth finding, not a supplement question
Legal status by region
Regulation differs considerably between jurisdictions and changes over time. This is a rough orientation, not legal advice — check the rules that apply where you are.
| Region | Regulatory status |
|---|---|
| United States | Sold as a dietary supplementNo pre-market safety evaluation applies to this category. |
| EU / UK | Not authorised as a novel foodLegal sale is restricted in the EU; it is nevertheless widely available online. |
| Canada / Australia | Not approved |
| Parts of Asia, Latin America & Middle East | Availability varies |
| Competitive sport | Not listedNot prohibited, but supplement contamination remains a practical risk. |