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Dubious testosterone boosters

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Last Updated on March 30, 2024 by Max


If you feel some symptoms of low testosterone or want to fortify your workout results and are thinking about purchasing a testosterone-booster supplement, hold on for a moment and read what you may don’t know and what may help you save your money and health. Most of the so-called T-boosters available on the market today have nothing to do with testosterone and do not affect your hormonal status in any way. Furthermore, some may even have hidden adverse effects that will be felt over time.

Start from the eye-opening research results about T-boosters: can we trust the sellers’ claims and product reviews? and how to analyze the ingredients of the supplement you chose for T-boosting capacity. You will know which ingredients are real, evidence-backed T-boosters and which are not.

Tribulus Terrestris

T. Terrestris is an invasive species widespread around the world. In the United States, it is deemed a harmful weed because its small woody fruit has long, sharp, and strong spines. 

T. Terrestris extract is widely used as a testosterone booster and is a part of many dietary supplements available on the market. However, in controlled studies, it failed to raise testosterone levels and did not show any anabolic qualities.  

Tribulus Terrestris in the Results of Evidence-Based Studies

In a study by Neychev and Mitev (2005), healthy young 20-36-year-old men consumed from 600 to 2000 mg of T. Terrestris a day for four weeks. Testosterone, androstenedione, and luteinizing hormone levels did not change at 24, 72, 240, 408, and 576 h from the beginning of the supplementation and were comparable with the placebo group. In a randomized, double-blind, and placebo-controlled study by C A Santos Jr et al. (2014), thirty men complaining of erectile dysfunction were randomized into two equal groups, and the experimental group received 800 mg of T. Terrestris a day for thirty days.  T. Terrestris was not more effective than placebo in improving symptoms of erectile dysfunction (International Index of Erectile Function) or serum total testosterone. 

Studies of the chemical composition of T. Terrestris have shown significant variations in the content of furostanol and spirostanol saponins, supposed to be in charge of their therapeutic action. Only T. Terrestris of Bulgarian origin showed the presence of steroidal saponin furostanol.  In a clinical trial by Z. Kamenov et al. (2017), 180 males with moderate erectile dysfunction were randomized equally into T. Terrestris and placebo groups. The experimental group of patients received six tablets a day of Tribestan, containing T. Terrestris of Bulgarian origin, which is standardized to furostanol (not less than 112.5mg) for three months.

Although the levels of serum testosterone were not evaluated in this study, the International Index of Erectile Function (Р<0.0001), Intercourse Satisfaction (p=0.0005), Libido (p=0.0038), and Overall Satisfaction (p=0.0028) were considerably improved in the study group compared to the placebo. No adverse effects were detected, and the therapy was well tolerated. With the contradictory results received by the studies worldwide, and given the vast differences observed in the chemical composition of the plants of different origins, the standardization of T. Terrestris extracts is an absolute necessity. 

Since T. Terrestris is widespread as a weed, it is very cheap and available in large quantities. Therefore, it is no wonder it is included as a major component of many male enhancement supplements, and the negative results of the experiments mentioned above are predictable. 


To sum up, I would question the quality of any supplement with T. Terrestris, or at least suggest studying carefully bioactive ingredients and the quantities the T. Terrestris extract includes before parting with money. So you will not waste your time and money.


  • Pokrywka, A. et al (2014). Insights into supplements with Tribulus terrestris used by athletes. Journal of Human Kinetics41 (1): 99–105.
  • Brown GA, et al (2000). Effects of anabolic precursors on serum testosterone concentrations and adaptations to resistance training in young men. International Journal of Sport Nutrition and Exercise Metabolism10 (3): 340–59.  
  • Brown GA, et al (2001). Endocrine and lipid responses to chronic androstenediol-herbal supplementation in 30 to 58 year old men. J Am Coll Nutr20 (5): 520–8. 
  • Neychev VK, Mitev VI (2005). The aphrodisiac herb Tribulus terrestris does not influence the androgen production in young men. Journal of Ethnopharmacology101 (1–3): 319–23. 
  • C A Santos Jr et al. (2014) Tribulus terrestris versus placebo in the treatment of erectile dysfunction: A prospective, randomized, double blind study. Actas Urol Esp May;38(4):244-8.
  • Z. Kamenov et al (2017) Evaluation of the efficacy and safety of Tribulus terrestris in male sexual dysfunction-A prospective, randomized, double-blind, placebo-controlled clinical trial. Maturitas May;99:20-26.
  • R. Ștefănescu, et al. (2020) A Comprehensive Review of the Phytochemical, Pharmacological, and Toxicological Properties of Tribulus terrestris L Biomolecules. May 12;10(5):752

Horny Goat Weed (​​Epimedium)

Epimedium Extract (Horny Goat Weed) found a wide range of uses in Traditional Chinese Medicine. but the most frequently used is the treatment of sexual dysfunction. The active substance of horny goat weed determining its therapeutic benefits is icariin, a flavonol glycoside extracted from the aerial part of the plant. So depending on the purification method applied, the concentration of the bioactive substance in the extract may vary from less than 40% to 99%. 

Does Horny Goat Weed Extract Affect Serum Testosterone Levels?

Most work supporting the role of Epimedium extract in enhancing erectile function has been conducted in rodent models, and no human clinical studies have been conducted so far. 

Researchers found that the treatment of rats with horny goat weed extract improves erectile function. Makarova and colleagues reported that icariin increases the frequency of matings and decreases the latency period between ejaculations in aged male rats treated with icariin at 300 or 750 mg/kg doses for ten days.

As to testosterone boosting activity of the Epimedium Extract, the available evidence-based data are contradictory. Zhang et al. found that chemically castrated rodents in the icariin group improved the condition of the reproductive organs and had higher serum testosterone levels compared with intact animals. On the contrary, Liu et al. did not reveal a difference in testosterone levels between the icariin group and controls. And Alan and colleagues reported that icariin exerts a dose-dependent inhibiting effect on serum testosterone levels. So we cannot claim with certainty whether Horny Goat Weed extract affects serum testosterone levels or not. 

How Does Horny Goat Weed Extract Affect Erectile Function?   

The well-established erectogenic effect of icariin extract is based on its inhibitory activity against phosphodiesterase type 5 (PDE5) on the one hand and upregulation of the enzymes, nitric oxide synthases, on the other hand. Nitric oxide synthases are enzymes catalyzing the production of nitric oxide from L-arginine. During an erection, nitric oxide relaxes smooth muscles lining blood vessels, thus increasing blood flow into the penis. An enzyme PDE5, on the contrary, can block that process, preventing blood from staying in the arteries and causing erectile dysfunction.

PDE5 inhibitors are the drugs most commonly used for the rehabilitation of erectile function in humans. Sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra) are PDE5 inhibitors clinically designated for the therapy of erectile dysfunction. Although the inhibitory effect of natural icariin extract on PDE5 is much weaker than that of its trading analogs, a slight modification of native icariin was shown to enhance the PDE5 inhibitory activity 80-fold, near the level of sildenafil.

Despite the mentioned qualities of the horny goat weed, there are not many scientific data to back it up as a medically sound supplement.

Side Effects and Warnings

The reported side effects include rapid heartbeat, upset stomach, dry mouth, nosebleeds, and dizziness. However, Epimedium extract may have adverse effects if you have cardiovascular diseases or are on steroids (like cortisone, prednisone, prednisolone); aromatase inhibitors (like letrozole); blood thinners; and nitroglycerin. If you are already on any medication, talk with your healthcare provider before taking horny goat weed.

Literature cited

  • Peter H. C. Lim (2017) Asian herbals and aphrodisiacs used for managing ED. Transl Androl Urol. 2017 Apr; 6(2): 167–175.
  • Alan W. Shindel et al (2010). Erectogenic and Neurotrophic Effects of Icariin, a Purified Extract of Horny Goat Weed (Epimedium spp.) In Vitro and In Vivo. J Sex Med. 2010 Apr; 7(4 Pt 1): 1518–1528.
  • Mario D. et al. (2008) Potent Inhibition of Human Phosphodiesterase-5 by Icariin Derivatives. J. Nat. Prod. 2008, 71, 9, 1513–1517.
  • Ning H, Xin ZC, Lin G, Banie L, Lue TF, Lin CS. (2006) Effects of icariin on phosphodiesterase-5 activity in vitro and cyclic guanosine monophosphate level in cavernous smooth muscle cells. Urology. 2006 Dec; 68(6):1350-4.
  • Zhang ZB, Yang QT. (2006) The testosterone mimetic properties of icariin. Asian J Androl. 2006 Sep; 8(5):601-5.
  • Liu WJ, Xin ZC, Xin H, Yuan YM, Tian L, Guo YL (2005) Effects of icariin on erectile function and expression of nitric oxide synthase isoforms in castrated rats. Asian J Androl. 2005 Dec; 7(4):381-8.
  • Makarova MN, et al (2007) Effect of lipid-based suspension of Epimedium koreanum Nakai extract on sexual behavior in rats. J Ethnopharmacol. 2007 Dec 3; 114(3):412-6.

Yohimbe (Pausinystalia Yohimbe)

Yohimbe is a bark of a tree Pausinystalia Yohimbe originating from the West African Countries. Do not confuse Yohimbe bark with Yohimbine- alkaloid – a chemical derived from the Yohimbe tree. Yohimbine has a dual aphrodisiac function: 1. it blocks alpha-2 adrenergic receptors allowing vasodilation in the pelvic area and thus improving sexual function, and 2. it increases serotonin in the brain, thereby boosting arousal.  

Standardized Yohimbine is available as a prescription drug for erectile dysfunction in the United States. It also is used in veterinary medicine to reverse sedation in dogs and deer.

Does Yohimbe Extract Affect Serum Testosterone Levels?

While Yohimbine has been prescribed as a treatment for erectile dysfunction, its clinical benefits have been reported to be much less than that of the PDE5 inhibitor drugs. The extracts from the Yohimbe bark marketed as dietary supplements- testosterone boosters contain highly variable quantities of Yohimbine, if any; no scientific evidence supports their efficacy. And no impact of Yohimbine drug or Yohimbe bark extract on testosterone levels has been reported so far. A recent analysis of 49 brands of Yohimbe supplements on the US market showed that some of the Yohimbine were either synthetic or from highly processed plant extract.

Is It Safe to Use Supplements Containing Yohimbe Extract?

Yohimbine is used as an active component in some medicinal products for which adverse effects are described. Side effects of using Yohimbe include heart attacks, seizures, nervousness, anxiety, high blood pressure, insomnia, increased heart rate, headache, nausea, and tremors.

European Union and US National Institute of Health declared Yohimbe bark extract and Yohimbine specifically as inadequately studied and possibly harmful to consume.

On request from the European Commission, in 2013, the Panel on Food Additives and Nutrient Sources added to Food provided a scientific opinion evaluating the safety of the use of Yohimbe bark and its preparations. The Panel concluded that the chemical and toxicological characterization of Yohimbe bark and its preparations for use in food is not adequate to conclude their safety as ingredients of food, e.g., in food supplements. 


A search of the scientific literature published so far reveals that there is no evidence to say that Yohimbe extract increases blood testosterone levels. Moreover, all extracts are extremely diverse in their composition, not standardized, and may be dangerous for your health.

Are you still hesitant and inclined to believe the numerous reviews of “happy” online Yohimbe shoppers? Then check it for yourself. Or have you already checked and have your opinion? Share it in the comments.


  • Beille, P. E. (2013). “Scientific Opinion on the evaluation of the safety in use of Yohimbe (Pausinystalia yohimbe)”. EFSA Journal11: 1–46.
  • “Yohimbe”. National Center for Complementary and Integrative Health, US National Institutes of Health. July 2012. Retrieved 2016-03-10.

Saw Palmetto (Serenoa Repens)

You can find comprehensive information about Saw Palmetto: “Does Saw Palmetto work in treating enlarged prostate symptoms?”.  A recent literature search by A. W. Pastuszak (2019) showed that most of the studies couldn’t find any T-boosting effect of Saw Palmetto

However, Saw Palmetto has long been known for its 5α-reductase inhibitory effect. 5α-reductase is an enzyme converting testosterone into its more potent form, 5α-dihydrotestosterone, which has a stronger affinity to the androgen receptors than testosterone. Thus, preventing this conversion, on one hand, Saw palmetto may save some extra testosterone in the blood, but on the other hand, it will result in a 2-3 fold reduction of the androgenic effect of the hormone. The consequent aromatization of testosterone to estradiol may cause breast enlargement, impotence, decreased libido, and decreased ejaculate volume- the known side effects of 5AR inhibitor drugs.

So, if you are not using the 5α-reductase inhibitory effect of Saw Palmetto for prostate issues or hair loss prevention, try to avoid the supplements including Saw Palmetto as a T-booster ingredient.

Maca Root Extract

A recent literature search by A. W. Pastuszak (2019) found NEGATIVE or NO effect of Maca root powder on blood testosterone levels. 

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2 thoughts on “Dubious testosterone boosters”

  1. This seems like very useful information for men to know. Congratulations on a well-designed and detailed website, Max.

    I do find some of these medical reports to be a little too technical to really follow, but that doesn’t take away from the usefulness of the research.

    I had always heard of Saw Palmetto as a male enhancement herb too, interesting to know there doesn’t seem to be much evidence to back that up. Not yet, anyway.

    My only experience related to this issue is this: I used to get a shot for enhanced testosterone every 2 weeks, but I doubt it was a chemical that someone can buy on Amazon. I went to a doctor’s office (specializing in Endocrine conditions) and the doctor’s assistant gave me the shots. It was called Testosterone Cypionate and I had to have a prescription to get it from the pharmacy. I was only taking it to compensate for low energy though, not any prostate condition that I know of.

    1. Thank you, Bryce, for your comment. It’s my pleasure to know that you liked my blog. It’s really overloaded with technical words and phrases. Sometimes you have to choose between simplicity and completeness of the information. Anyway, thank you for your remark, I need to look into it.
      It’s great that you haven’t had any prostate issues. Most prostate problems show up after 50-55, so just be alert. Much easier to change one’s lifestyle and prevent them, than trying to treat them the rest of life.
      I know a little bit about TRT and Testosterone Cypionate. Unfortunately, testosterone replacement therapy has a whole list of side effects. And, once you’ve started it, you have to keep under the control the levels of the related steroids too, otherwise, it may end up deplorably. That’s why many men are trying to balance their T-level in alternative ways.
      Talk to your doctor about the possible side effects of TRT and how to prevent them.
      Have a great weekend!

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