The "libido" section is where the most is promised and the least is proven. A university andrology team sorted through it by rating each product sold according to ingredients that have clinical trials, at the dosage where they were tested: four out of five products have no expected efficacy. Not because nothing works, but because what works a little is rarely in the bottle, at the right dose.
This guide reports what clinical trials have measured, plant by plant, in men and women: maca, tribulus, and ginseng. It also identifies which "natural aphrodisiacs" carry risks that outweigh any benefit, and when a loss of desire calls for a medical consultation rather than a capsule.
The market. 80% of supplements for male sexuality analyzed by the University of Padua have no expected efficacy; the three ingredients identified by its meta-analysis are ginseng, tribulus, and L-arginine. Maca. Four randomized trials: effect on desire in healthy men and postmenopausal women, no effect in cyclists, effect on erectile function in one small trial. Limited evidence, with no hormonal effect, starting from eight weeks.
Tribulus. Better documented in women: 67 women with low desire showed significant improvement in desire, arousal, and satisfaction in four weeks; a review of five trials confirms this, with very low certainty. In men, mixed results on erectile function, no effect on testosterone. Ginseng is the best-documented ingredient for erectile function. To avoid : yohimbine, Spanish fly, mad honey. And persistent loss of desire has causes that no plant can treat.
The libido section, reviewed by andrologists
Dietary supplements for male sexual function are mixtures of active ingredients, sold mainly online. In randomized trials, the molecules they contain have shown variable degrees of efficacy, or no evidence at all. To evaluate the potential efficacy of formulations, products marketed in Italy were analyzed using a scoring system. A systematic review identified ingredients capable of improving erectile function and their minimum effective daily dose. The meta-analysis identified certain nutraceuticals, such as ginseng, tribulus, and L-arginine, capable of improving male sexual function. According to the score, 2 supplements, 8 percent, met the high expected efficacy group, 3, 12 percent, met the low efficacy group, and 20, 80 percent, met the criterion of no expected efficacy. Supplements are usually mixtures of many substances, frequently at negligible doses or with no evidence whatsoever.
Petre GC, Francini-Pesenti F, Vitagliano A, Grande G, Ferlin A, Garolla A. Nutrients 2023;15(17):3677. DOI: 10.3390/nu15173677
The mechanism is always the same: a product displays ten ingredients, of which two have a trial, at a dose ten times lower than that of the trial. The rest of this article therefore only discusses isolatedingredients, at the doses they were tested with. Our testosterone guide does the same work for "boosters," with the same result.
Maca: what four trials show
Seventeen databases were searched for all randomized trials of maca versus placebo in healthy people or those with sexual dysfunction. Four trials met the criteria. Two suggested a significant positive effect of maca on sexual dysfunction or desire, in healthy postmenopausal women and in healthy adult men respectively, while another showed no effect in healthy cyclists. The fourth evaluated maca in patients with erectile dysfunction, using the International Index of Erectile Function, and showed significant effects. The results provide limited evidence of maca's efficacy in improving sexual function; the number of trials, sample sizes, and methodological quality were too limited for firm conclusions.
Shin BC, Lee MS, Yang EJ, Lim HS, Ernst E. BMC Complement Altern Med 2010;10:44. DOI: 10.1186/1472-6882-10-44
The reference trial in men is from Cayetano Heredia University in Lima, published in Andrologia : 12 weeks, double-blind, with 1.5 or 3 g per day of gelatinized maca or placebo, in men aged 21 to 56 years. Sexual desire improved starting from the eighth week, and analysis shows that this effect was independent of mood, measured by depression and anxiety scales, as well as hormones: testosterone and estradiol did not change. A review by the same team, in Forschende Komplementärmedizin, notes that randomized trials also show favorable effects on energy and mood, and on sperm production, motility, and volume, always without changes in testosterone, LH, FSH, or prolactin.
Maca has a measured effect on desire, real and modest, in two trials in healthy people and one in men with erectile dysfunction, and one negative trial in athletes. It does not act not by hormones, making it an option where a hormonal active ingredient would not be, and through a mechanism that is not yet understood. The timeframe is eight weeks, with trial doses ranging from 1.5 to 3 g per day. It's both more and less than what marketing claims.
Tribulus: in women first
Sixty-seven women of childbearing age with hypoactive sexual desire disorder were randomized between tribulus extract and placebo for four weeks. Desire, arousal, lubrication, orgasm, satisfaction, and pain were measured using the Female Sexual Function Index. Thirty women from the placebo group and thirty from the tribulus group completed the study. At the end of the fourth week, patients in the tribulus group showed significant improvement in total score, desire, arousal, lubrication, satisfaction, and pain. The frequency of adverse effects was similar in both groups.
Akhtari E, Raisi F, Keshavarz M, et al. Daru 2014;22(1):40. DOI: 10.1186/2008-2231-22-40
A systematic review published in 2020 by a Brazilian evidence assessment team combined five randomized trials and 279 women: after one to three months of treatment, pre- and post-menopausal women randomized to tribulus showed a significant increase in sexual function scores, without serious adverse effects. However, its authors considered the certainty of evidence very low, which means that future trials could change these estimates, and they request that the decision be shared with the patient by discussing these uncertainties.
In men, the picture is different. Onerectile function, the meta-analysis from Drugs that we detail below includes two tribulus trials in 202 men and characterizes their results as mixed ; the Padua meta-analysis includes it among the three ingredients capable of improving male sexual function. On testosterone, it has no effect, as shown by the two systematic reviews cited in our testosterone guide. Tribulus is therefore a plant for desire and sexual function, better documented in women than in men, and not a hormonal plant.
Ginseng and erectile function
Twenty-four randomized trials including 2,080 patients with erectile dysfunction were identified. Twelve evaluated single-ingredient preparations: five of ginseng in 399 men, three of saffron in 397, two of tribulus in 202, one of maritime pine in 21, and one of maca in 50. Ginseng significantly improved erectile function, with a standardized mean difference of 0.43 on the IIEF-5 score and zero heterogeneity. Maritime pine and maca showed very preliminary positive results, saffron and tribulus showed mixed results. Only seven trials had a low risk of bias. The authors conclude there is encouraging evidence for ginseng, requesting larger, higher-quality studies before any recommendation.
Borrelli F, Colalto C, Delfino DV, Iriti M, Izzo AA. Drugs 2018;78(6):643-673. DOI: 10.1007/s40265-018-0897-3
If the question is erectile function rather than desire, the best-documented plant is neither maca nor tribulus: it is ginseng, with five consistent trials. And if the question is established erectile dysfunction, it is not a plant at all: the arteries of the penis are finer than those of the heart, and a persistently weakening erection is a recognized early cardiovascular warning sign that justifies a consultation before any supplement.
What to avoid
A review published in 2015 evaluated the best-selling aphrodisiacs according to research quality, efficacy, and safety. Its conclusion is clear: the risks of yohimbine, of Spanish fly called Spanish fly, from mad honey and from Bufo toad exceed any benefit, and these products should be avoided. Yohimbine, common in products sold online, raises blood pressure and causes anxiety and palpitations. The same review classifies maca, tribulus, ginkgo and ginseng among products with limited but emerging data.
An additional risk, not covered in the review: certain "libido" supplements purchased online contain undisclosed erectile dysfunction medications, whose combination with cardiac treatments can be dangerous. A product with spectacular effects within an hour is not a plant.
| Ingredient | Desire | Erectile Function | Hormones |
|---|---|---|---|
| Maca | Effect, limited evidence, men and postmenopausal women | Very preliminary, one trial | No effect |
| Tribulus | Effect in women, very weak certainty | Mixed results in men | No effect in men |
| Ginseng | Not evaluated here | Best documented, five trials | Not evaluated here |
| Yohimbine | To avoid | To avoid | Blood pressure elevation, anxiety, palpitations |
When loss of desire stems from something else
A sustained loss of desire most often has a cause that the supplements aisle cannot address. In both men and women: a depression, of which loss of desire is often one of the first signs; chronic stress and sleep deprivation, detailed in our cortisol guide ; a medication, with antidepressants and certain contraceptives leading the way; a relationship issue ; and in men, a low testosterone when the decrease in desire is accompanied by rare morning erections and less firm erections, which our article on low testosterone details.
471 mg of tribulus extract per day, standardized to 90% saponins. A randomized trial against placebo in 67 women with decreased desire measured improvement in desire, arousal, and satisfaction in four weeks; a review of five trials confirms this, with certainty rated as very low. Three capsules per day, 40 days.
View TribulusTribulus does not increase testosterone in men. Not recommended during pregnancy and breastfeeding, and without medical advice in case of hormone-dependent conditions.
Choose what fits you best: the answer appears just below.
This is the situation in trials: healthy people with declining desire. Maca showed an effect after eight weeks, without affecting hormones, in men and postmenopausal women. 1.5 to 3 g per day in trials. In women, tribulus is the other option, with greater uncertainty.
Chronic stress, lack of sleep, low mood, and multiple medications lower desire, and no plant can compensate for this. It is the cause that must be treated, with a doctor if treatment is involved: never modify an antidepressant on your own. Maca can support, but it does not replace treatment.
Declining desire, morning erections, and decreased firmness together are precisely the three symptoms specifically linked to low testosterone in the European EMAS study. A fasting morning test, repeated, before any plant. And an erection that weakens durably should be discussed with a doctor, because it can signal a cardiovascular problem.
Four out of five products analyzed by andrologists have no expected efficacy, because their ten ingredients are at negligible doses or lack data. And an effect "guaranteed" in one hour signals an undeclared medication, not a plant. If the question is erection, ginseng has trials; if it is desire, maca.
This test guides you, it does not replace the advice of a healthcare professional.
Frequently asked questions
The plants
Do libido supplements work?
Most of those sold do not. A team from the andrology department at the University of Padua analyzed supplements for male sexuality marketed in Italy and rated them according to ingredients with trial evidence and their minimum effective dose: 8% met the high expected efficacy group, 12% the low efficacy group, and 80% met the no expected efficacy criterion. Products are most often blends of ingredients at negligible doses or lacking data. Their meta-analysis identifies three ingredients capable of improving male sexual function: ginseng, tribulus, and L-arginine.
Does maca increase libido?
With limited evidence, yes. A systematic review conducted by Edzard Ernst's team compiled four randomized placebo-controlled trials: two show a positive effect on desire or sexual function, in healthy men and postmenopausal women, one shows nothing in cyclists, and one shows an effect in men with erectile dysfunction. The reference trial in men, 12 weeks at 1.5 or 3 g per day, measures an improvement in desire from the eighth week onwards, independent of mood and without hormonal changes. The review authors conclude limited evidence, on samples too small for firm conclusions.
Does maca work in women?
One of the four trials in the systematic review involved healthy postmenopausal women and showed a positive effect on sexual function. It is one trial, not a body of literature, and the review states this. Maca does not act through hormones; trials in men show no variation in testosterone or estradiol, making it a viable option where a hormonal agent would not be, without yet knowing by what mechanism it acts.
Does tribulus increase libido in women?
This is the area where it has the most data. A randomized double-blind placebo-controlled trial included 67 women of reproductive age with hypoactive sexual desire disorder, treated for four weeks with tribulus extract or placebo: total sexual function score, desire, arousal, lubrication, satisfaction, and pain all significantly improved, with no more side effects than placebo. A systematic review of five trials and 279 women confirms an increase in sexual function scores in women before and after menopause, but judges the certainty of the evidence very low.
Does tribulus work in men?
On erection, results are mixed: the meta-analysis of 24 trials published in Drugs includes two tribulus trials in 202 men and qualifies them as mixed results. The Padua meta-analysis includes it among the three ingredients capable of improving male sexual function. On testosterone, it does nothing, as detailed in our testosterone guide. Tribulus is therefore a plant for desire and sexual function, better documented in women than in men, and not a hormonal plant.
What is the best supplement for erection?
Ginseng, according to the meta-analysis of 24 trials and 2,080 patients published in Drugs : five trials in 399 men show a significant improvement in erectile function score compared to placebo, with a standardized difference of 0.43 and zero heterogeneity. The authors speak of encouraging evidence and call for larger trials. Tribulus and saffron give mixed results, maca and maritime pine very preliminary results. Established erectile dysfunction remains a reason for consultation, because it can signal a cardiovascular problem.
How long does maca take to work?
In the reference trial, the effect on desire appeared from the eighth week and was maintained at twelve. Nothing should be judged before two months. The doses in the trials range from 1.5 to 3 g per day of gelatinized maca.
Safety and consultation
Which natural aphrodisiacs are dangerous?
A review in Sexual Medicine Reviews is clear: yohimbine, cantharid fly also called Spanish fly, mad honey and the Bufo toad have risks that outweigh any benefit and should be avoided. Yohimbine in particular raises blood pressure and causes anxiety and palpitations. The same review classifies maca, tribulus, ginkgo and ginseng among products with limited but emerging data. A libido supplement purchased online may also contain undisclosed erectile medications, which is a real risk with certain heart treatments.
When should you consult for a decrease in libido?
When it lasts, when it weighs on you, or when it is accompanied by other signs. In men, a decrease in desire with rare morning erections and less firm erections points toward testosterone testing, described in our article on low testosterone ; established erectile dysfunction warrants consultation because it can reveal a cardiovascular problem. In women as in men, a decrease in desire often accompanies depression, chronic stress, lack of sleep, relationship conflict, or medication, with antidepressants and contraceptives leading the way. No plant treats these causes.
What to remember about libido and supplements?
That 80% of products sold have no expected efficacy. That maca has limited but real evidence on desire, in men and postmenopausal women, without hormonal effect, from eight weeks onward. That tribulus is better documented in women with decreased desire than in men, with very weak certainty. That ginseng is the best-documented ingredient for erectile function. That yohimbine and exotic aphrodisiacs should be avoided. And that a decrease in libido that persists should be discussed, because its frequent causes are not treated with a plant.
Glossary
- Hypoactive sexual desire disorder
- Persistent decrease or absence of sexual desire causing distress; the diagnosis in women from the tribulus trial.
- FSFI
- Female Sexual Function Index: validated questionnaire measuring desire, arousal, lubrication, orgasm, satisfaction and pain.
- IIEF-5
- International Index of Erectile Function, short version; the criterion of the meta-analysis on erectile function.
- Standardized mean difference
- Effect size independent of the unit of measurement; 0.43 for ginseng is a moderate effect.
- Certainty of evidence
- Degree of confidence in a result according to the GRADE method; "very weak" means that future trials could change it.
- Gelatinized maca
- Maca root heated to eliminate starch and concentrate active compounds; the form used in Peruvian trials.
- Yohimbine
- Alkaloid extracted from yohimbe bark, present in many online products; raises blood pressure and causes anxiety and palpitations.
Sources
The studies cited below were identified via PubMed.
- Petre GC, Francini-Pesenti F, Vitagliano A, Grande G, Ferlin A, Garolla A. Dietary supplements for erectile dysfunction: analysis of marketed products, systematic review, meta-analysis and rational use. Nutrients, 2023;15(17):3677. DOI
- Borrelli F, Colalto C, Delfino DV, Iriti M, Izzo AA. Herbal dietary supplements for erectile dysfunction: systematic review and meta-analysis. Drugs, 2018;78(6):643-673. DOI
- Shin BC, Lee MS, Yang EJ, Lim HS, Ernst E. Maca for improving sexual function: systematic review. BMC Complementary and Alternative Medicine, 2010;10:44. DOI
- Gonzales GF, Córdova A, Vega K, et al. Effect of Lepidium meyenii (maca) on sexual desire and its lack of relationship with serum testosterone in healthy adult men. Andrologia, 2002;34(6):367-372. DOI
- Gonzales GF, Gonzales C, Gonzales-Castañeda C. Lepidium meyenii (maca): a plant from the Peruvian highlands, from tradition to science. Forschende Komplementärmedizin, 2009;16(6):373-380. DOI
- Akhtari E, Raisi F, Keshavarz M, et al. Tribulus in the treatment of sexual dysfunction in women: randomized double-blind placebo-controlled trial. DARU Journal of Pharmaceutical Sciences, 2014;22(1):40. DOI
- Martimbianco ALC, Pacheco RL, Vilarino FL, Latorraca COC, Torloni MR, Riera R. Tribulus in female sexual dysfunction: systematic review. Revista Brasileira de Ginecologia e Obstetrícia, 2020;42(7):427-435. DOI
- West E, Krychman M. Natural aphrodisiacs: review of a selection of sexual stimulants. Sexual Medicine Reviews, 2015;3(4):279-288. DOI
