Fadogia agrestis is the shrub that Andrew Huberman put on the map. In podcast episode after podcast episode he highlighted it as one of the most interesting natural interventions for testosterone in men - and suddenly a relatively obscure West African herbal supplement was on everyone's lips in the biohacking community.
But what does the research actually say? The honest version is more nuanced - and more interesting - than the marketing. This guide goes through the mechanism, the studies, the safety discussion and why fadogia agrestis nevertheless has a legitimate place in a testosterone stack.
What is fadogia agrestis?
Fadogia agrestis is a flowering shrub in the Rubiaceae family (the same family as coffee) growing naturally in Nigeria, Cameroon, Angola and Zambia. It grows 30-90 cm tall with woody stems and yellow flowers. In West African traditional medicine it has long been used as an aphrodisiac and vitality-enhancing preparation.
It is the stems - not the roots or leaves - that contain the highest concentration of active compounds. That is why it is important to check that supplements state stem extract on the label. The stems contain alkaloid and saponin compounds thought to be responsible for the physiological effects.
The mechanism - why LH is the key
Testosterone production in the body is governed by a hormonal cascade:
- Hypothalamus releases GnRH (gonadotropin-releasing hormone)
- GnRH signals the pituitary to release LH (luteinising hormone)
- LH signals the Leydig cells in the testes to produce testosterone
Fadogia agrestis is thought to act primarily via steps 2-3 of this chain: the saponin and alkaloid compounds in stem extract appear to stimulate LH release from the pituitary, which in turn drives increased testosterone synthesis in the testes. Some research also suggests fadogia may increase sensitivity in LH receptors - meaning the Leydig cells respond better to the LH signal.
This is a mechanistically distinct pathway compared to tongkat ali, which primarily acts via SHBG release. That is the reason the fadogia + tongkat ali stack is popular: they address testosterone via complementary mechanisms.
What does research say - the honest review
Here it is important to be clear: there are no published human studies on fadogia agrestis yet. All direct evidence comes from animal models, primarily male rats. This makes fadogia one of the more speculative ingredients in testosterone stacks.
The key study (Yakubu et al., Asian Journal of Andrology, 2005)
The most cited study gave water-based stem extract of fadogia agrestis to male albino rats for three days at doses of 18, 50 and 100 mg/kg bodyweight. Results were striking: at 18 mg/kg testosterone approximately doubled versus the control group. Dose-dependent response at higher doses. All tested doses also improved sexual behaviour. The mechanism was interpreted as LH-mediated.
Follow-up study - testicular size and 28 days
A follow-up study by the same research group (Yakubu et al.) gave the same doses for 28 days. Fadogia treatment significantly increased testicular size - probably via stimulated cell proliferation in the testes, a proxy for increased testosterone production capacity. Also rat data.
The important caveat: toxicology at high doses
A critical study (Yakubu et al., 2008) investigated liver toxicity at high doses in rats and found signs of liver and kidney impact at high doses over longer periods. This is why Huberman and other experts consistently recommend: keep to lower doses (300-600 mg/day), cycle the supplement (3 weeks on, 1 week off), and monitor bloodwork (liver enzymes, testosterone, LH) with longer use.
Huberman's position: Fadogia agrestis has potential for testosterone support via the LH receptor mechanism but lacks long-term human safety data. Cycling and blood test follow-up are clearly recommended.
Who might benefit from fadogia agrestis?
- Most suitable for: Men over 30 who have already optimised the fundamentals (sleep, diet, training, stress management) and want to add hormonal support. Not a foundational supplement - an experimental adjunct.
- In combination with tongkat ali: The most popular stack. If you choose to try fadogia, combine with tongkat ali for complementary mechanisms.
- Not suitable without follow-up: If you plan longer protocols, monitor bloodwork - at minimum testosterone, LH and liver enzymes (ALT/AST).
- Not suitable: Younger men with normal testosterone, pregnant or breastfeeding women, people with liver or kidney disease.
Dosage and protocol
- Most common dose: 300-600 mg/day of stem extract
- Extract vs raw powder: Choose standardised stem extract, not leaf or root powder without standardisation
- Cycling: 3 weeks on / 1 week off - based on the safety precautionary principle
- Timing: Take with food, preferably morning or mid-morning
- Avoid: Doses above 1,000 mg/day based on toxicology findings in animal studies
Fadogia in a longevity stack
- Fadogia + Tongkat Ali: Complementary LH and SHBG mechanisms. The most common biohacking stack.
- Fadogia + Zinc: Zinc is a cofactor for testosterone. Deficiency is common and directly hormone-affecting.
- Fadogia + Ashwagandha: Ashwagandha lowers cortisol (which otherwise suppresses testosterone production). Addresses the stress component.
Find Noop's Fadogia Agrestis in our hormones and libido collection.
FAQ
Are there human studies on fadogia agrestis?
No, as of 2026 there are no published randomised human studies. All direct research is from rat studies. That is the central limitation.
Is fadogia agrestis legal?
Yes. It is classified as a dietary supplement and is legal to sell and buy in the EU. It is not banned by WADA.
Why does Huberman recommend cycling fadogia?
Because the absence of long-term safety data makes cycling a precautionary principle. Animal studies showed liver and kidney impact at high doses, and without human data we do not know the safety profile at continuous use over months.
How does fadogia differ from tongkat ali?
Tongkat ali primarily acts via SHBG release (releasing bound testosterone) and LH stimulation with more human data. Fadogia hypothetically acts more directly on LH receptors in the testes. The mechanisms are complementary, which is the basis for the stack's popularity.
Can women take fadogia agrestis?
There is no data on effects in women. The supplement targets primarily male testosterone production via the LH-Leydig cell axis. Pregnant and breastfeeding women should avoid it.