herb · for low stamina
Tongkat Ali
Thought to support testosterone, which in turn supports physical performance.
Say that in clinical terms
Supports testosterone production and provides ergogenic performance enhancement via hormonal optimization.
How strong is the research?
Mixed evidence
A small trial of 18 rugby players found no measurable difference after seven days.
Studied in a narrower groupIndustry funded
3 papers read, 2 supporting, 1 against.
Tested as: Physta® standardised aqueous root extract of Eurycoma longifolia (Biotropics Malaysia Berhad)
Who was studied: The underlying trials mostly studied men with sexual health problems.
How much to take
daily
200–400 mg
Testosterone support may enhance endurance and strength in men.
Before you take it
- No established NIH ODS Tolerable Upper Intake Level (UL) for Eurycoma longifolia; no government body has set a formal UL for this botanical.
- Increases free testosterone and reduces sex hormone-binding globulin (SHBG); contraindicated in prostate cancer and other androgen-sensitive conditions.
- Contraindicated in pregnancy and lactation; no safety data exist in these populations.
- Documented pharmacokinetic drug interaction: water-based extract reduces propranolol bioavailability by 29% and Cmax by 42% in a single-blinded crossover study (Salman et al. 2010, PMID 21054461, n=14); mechanism is absorption-mediated rather than metabolic.
- In vitro data suggest potential CYP3A4 inhibition; clinical significance in humans is unconfirmed; precautionary caution is warranted with CYP3A4-metabolized drugs (statins, clopidogrel, immunosuppressants).
- Rare case reports of drug-induced liver injury (elevated transaminases, jaundice); NIH LiverTox maintains a Tongkat Ali entry; contraindicated with pre-existing liver disease.
- Precautionary contraindications with pre-existing kidney disease, heart disease, diabetes, and sleep apnea appear in product labeling and traditional-medicine guidance; direct clinical evidence supporting these specific contraindications is limited.