I’ve been noticing fenugreek mentioned everywhere lately. I’ve seen it in numerous videos, supplements and social media posts with great promises attached. “Eat this and it will boost your testosterone and improve your sex life”. There are many confident claims so I was curious about what evidence there is to back them up.
This gap between confident claims and scientific research is exactly why I got started with this blog. I’m interested in the feelings around sex; not the mechanics. Since the release of Viagra we can leave the mechanics to the pharmaceutical industry.
What the research shows is slightly more complicated than the simple claims but useful and considerably more interesting. Fenugreek turns out to be a genuinely interesting case study.
A note on safety
There are known drug interactions with fenugreek. If you’re on blood thinners, diabetes medications metformin, insulin or sulfonylureas, asthma medication theophylline, ED medication sildenafil, are pregnant or have an allergy to chickpeas, peanuts or soybeans, double check before combining them with fenugreek.
What fenugreek is supposed to do
Fenugreek (Trigonella foenum-graecum) is a common herb used in South Indian, Ethiopian, Turkish and Egyptian cuisine. It smells a bit like maple syrup and is used to make artificial maple syrup flavouring.
Fenugreek is marketed as a natural testosterone booster. The active compound is protodioscin. This is a plant chemical thought to affect how the body processes male sex hormones¹. The main implication is: raise testosterone; raise desire. It is well established that the male hormone testosterone plays a significant role in desire.
A study in 2020 that looked at research data from four earlier trials concluded that fenugreek did in fact affect total testosterone levels in men. It was seen to be a modest effect but it was definitely happening.
However when I dug a little deeper a few things stood out. Testosterone does affect desire but it is not the only factor.
The initial research that built the reputation
Dr Steels and colleagues in 2011² studied 60 healthy men, ages 25–52. They gave them 600mg Testofen daily for 6 weeks and found significant improvements in libido scores on the DISF-SR questionnaire. Testofen is a proprietary fenugreek extract made by Gencor. None of the participants had erectile dysfunction at the start of the trial.
Then in a separate study Dr Rao and colleagues³ tested 120 healthy men aged 43–70 and gave them 600mg Testofen for 12 weeks. They found reductions in age-related decline symptoms, increases in testosterone and improvements in sexual function scores.
These are relatively small numbers of people but it seems to show that fenugreek increases libido.
The 2024 Oslo trial: what it found
Scientists Lee-Ødegård, Gundersen and Drevon⁴ studied 95 men between the ages of 40 and 80. It was a double-blind trial, i.e. neither the researchers nor the participants knew who received the placebo. It lasted 12 weeks and tested four different fenugreek daily doses: placebo, 600mg, 1200mg and 1800mg.
The results were that testosterone levels in the blood rose by 13% for those taking fenugreek. Even the placebo group rose by 9%, so the difference was not statistically significant. However the saliva testosterone levels showed a marked difference. Those taking fenugreek had 37.2% higher levels of testosterone in their saliva.
And they found no effect on libido. They gave questionnaires to all the participants before and after and did not see a statistically significant difference.
The gap between the hormone and the wanting
The salivary testosterone result is real. Fenugreek appears to raise free testosterone i.e. the biologically active form that can bind to receptors. But in the 2024 Norwegian study it didn’t produce a measurable increase in libido. That directly contradicts the Steels 2011 study.
Even in healthy young men the relationship between day-to-day fluctuations in testosterone levels and desire doesn’t tally.7 Just because their testosterone rises on a particular day it doesn’t mean that they are going to feel more lust.
The Endocrine Society’s clinical practice guidelines are pretty clear that treatment with testosterone for men with diagnosed, clinically low testosterone gives great improvements in libido and erections and sexual activity.⁵⁶ But for men who already have normal levels of testosterone, adding more testosterone doesn’t give any further significant improvements.5
For women it’s a different and more complex situation. The evidence for benefit is strongest in postmenopausal women. Increasing the testosterone levels in women can increase libido but the threshold between helpful and too much is smaller than it is for men. Excess can cause masculinisation such as facial hair growth, voice deepening, hair loss, acne and clitoral enlargement.⁸⁹
What this means in practice
Fenugreek is doing something to increase levels of free testosterone in the saliva. There are two studies that support the claim that it also increases libido; one study that doesn’t. All three of these trials were relatively small in scale.
So if your desire is low and this is due to low testosterone it seems that fenugreek may well help you. And there’s a chance that it will increase libido even if your testosterone is normal but there’s less evidence for that. The studies that found positive results used 600mg of Testofen daily. That’s the dose with the most evidence behind it and the sensible place to start.
It is worth remembering that the two Testofen studies were funded by Gencor, the manufacturer of the extract. The Oslo trial was funded and run by Vitas, a commercial laboratory; two of the three authors have financial stakes in the company. I’m not saying that skewed the results but it is worth factoring in when weighing the evidence.
Self Experimentation
So I’m going to try this out for myself and see what happens. Over the next three months I’m going to take 600mg of standardised extract of fenugreek and see what it does for my libido. I’m on medication that has a side effect of reducing libido so let’s see if fenugreek reverses that. I’ll let you know in three months’ time.
Verified citations
- Mansoori A, Hosseini S, Zilaee M, Hormoznejad R, Fathi M. Effect of fenugreek extract supplement on testosterone levels in male: a meta-analysis of clinical trials. Phytother Res. 2020;34(7):1550–1555. https://pubmed.ncbi.nlm.nih.gov/32048383/
- Steels E, Rao A, Vitetta L. Physiological aspects of male libido enhanced by standardized Trigonella foenum-graecum extract and mineral formulation. Phytother Res. 2011;25(9):1294–1300. https://pubmed.ncbi.nlm.nih.gov/21312304/
- Rao A, Steels E, Beccaria G, Inder WJ, Vitetta L. Testofen, a specialised Trigonella foenum-graecum seed extract reduces age-related symptoms of androgen decrease, increases testosterone levels and improves sexual function in healthy aging males in a double-blind randomised clinical study. Aging Male. 2016;19(2):134–142. https://pubmed.ncbi.nlm.nih.gov/26791805/
- Lee-Ødegård S, Gundersen TE, Drevon CA. Effect of a plant extract of fenugreek (Trigonella foenum-graecum) on testosterone in blood plasma and saliva in a double blind randomized controlled intervention study. PLoS One. 2024;19(9):e0310170. https://pmc.ncbi.nlm.nih.gov/articles/PMC11407615/
- Bhasin S, Brito JP, Cunningham GR, Hayes FJ, Hodis HN, Matsumoto AM, Snyder PJ, Swerdloff RS, Wu FC, Yialamas MA. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715–1744. https://academic.oup.com/jcem/article/103/5/1715/4939465
- Rizk PJ, Kohn TP, Pastuszak AW, Khera M. Testosterone therapy improves erectile function and libido in hypogonadal men. Curr Opin Urol. 2017;27(6):511–515. https://pmc.ncbi.nlm.nih.gov/articles/PMC5649360/
- Catena T, Crewther BT, Eisenbruch AB, Grillot RL, Maestripieri D, Roney JR. Day-to-day associations between testosterone, sexual desire and courtship efforts in young men. Proc Biol Sci. 2024;291(2035):20241508. https://pmc.ncbi.nlm.nih.gov/articles/PMC11597408/
- Reed BG, Bou Nemer L, Carr BR. Has testosterone passed the test in premenopausal women with low libido? A systematic review. Int J Womens Health. 2016;8:599–607. https://pmc.ncbi.nlm.nih.gov/articles/PMC5066846/
- Uloko M, Rahman F, Puri LI, Rubin RS. The clinical management of testosterone replacement therapy in postmenopausal women with hypoactive sexual desire disorder: a review. Int J Impot Res. 2022. doi:10.1038/s41443-022-00613-0. https://pmc.ncbi.nlm.nih.gov/articles/PMC9674516/
The content on this site is for informational purposes only and does not constitute medical advice. Always consult a qualified doctor before starting any supplement, particularly if you are taking prescription medication.
The Desire Dispatch
Once a week I share something I’m currently thinking about, experimenting with, or reading in the research. It’s personal, it’s unfiltered, and it contains things that don’t make it into the blog. Free to subscribe.