Maca Root (Lepidium meyenii)
A root vegetable grown at altitude in the Peruvian Andes, cultivated there for centuries and used traditionally to support stamina, energy, and fertility.
What the research found. Gonzales and colleagues ran a 12-week double-blind, placebo-controlled, randomised trial in men aged 21 to 56, published in Andrologia in 2002. Participants took 1,500mg or 3,000mg of gelatinised Maca daily. Self-reported sexual desire improved from week 8 onwards. Serum testosterone and oestradiol were unchanged, which means the effect did not run through hormones.
What it does not show. The outcome was self-reported desire rather than erectile function, it is a single trial, and the effect took two months of daily dosing to appear. Nothing here indicates an acute effect.
Panax Ginseng
A perennial root native to East Asia with more than two thousand years of recorded use as a tonic for energy and vitality. It is pharmacologically distinct from American ginseng and Siberian ginseng, which are different plants despite the shared name.
What the research found. This is the most studied ingredient in the formula. A Cochrane systematic review published in 2021 pooled nine placebo-controlled studies. Its conclusion was that ginseng appears to have a trivial effect on erectile dysfunction against placebo on the erectile function domain of the IIEF-15, at low certainty of evidence. It may improve self-reported ability to have intercourse, again at low certainty.
What it does not show. The review authors noted that most included studies were supported by, or in communication with, ginseng production companies, so publication bias and favourable reporting cannot be discounted. Trials again used sustained daily dosing.
Damiana (Turnera diffusa)
A small aromatic shrub from Mexico and Central America, used as an aphrodisiac by indigenous peoples of northern Mexico and added to the United States pharmacopoeia as a tonic in 1874.
What the research found. A 2013 study in the Journal of Ethnopharmacology examined an aqueous Damiana extract in male rats and concluded that its pro-sexual effects involve the nitric oxide pathway, the same vascular mechanism relevant to erectile physiology.
What it does not show. This is an animal study. There is no randomised controlled trial of Damiana in men. Damiana is in the formula for its long traditional use and its complementary role alongside the other three ingredients.
Ginkgo Biloba
One of the oldest surviving tree species on earth, used in traditional Chinese medicine for centuries and studied extensively for its effects on peripheral circulation.
What the research found. An open trial published in 1998 reported Ginkgo to be 84% effective in treating antidepressant-induced sexual dysfunction. A 2021 systematic review of five randomised controlled trials covering 475 participants found positive effects on sexual function in postmenopausal women, no effect in people taking antidepressants, and concluded that Ginkgo has limited positive effects on sexual function overall, with more research needed.
What it does not show. The 1998 trial had no placebo group, which is why its 84% figure should be treated with caution, and it drew published criticism at the time. None of the controlled trials in the systematic review studied men with erectile difficulty. Ginkgo is in the formula on a circulatory rationale.
The Four Ingredients at a Glance
| Ingredient | Traditional use | Strongest study | What it found |
|---|---|---|---|
| Maca Root | Stamina, energy, fertility | Randomised placebo-controlled trial, 12 weeks, men | Improved self-reported desire from week 8, no hormone change |
| Panax Ginseng | Energy, endurance, vitality tonic | Cochrane review, nine studies | Trivial effect versus placebo, low certainty of evidence |
| Damiana | Aphrodisiac, tonic | Animal study, rats | Pro-sexual effect involving the nitric oxide pathway |
| Ginkgo Biloba | Circulation, cognitive support | Systematic review, five trials, 475 participants | Limited positive effects, none studied in men with erectile difficulty |
What Is Not in It
The formula contains no synthetic chemicals and no proprietary blend. It also contains none of the following, which appear routinely in this category:
- Yohimbe, associated with raised blood pressure and anxiety
- Tongkat Ali
- Tribulus Terrestris
- Horny Goat Weed
- Undeclared pharmaceutical compounds, which are a recurring problem in unregulated male supplements
Four ingredients, all named on this page and on the pack.
Safety and Interactions
Plant-based does not mean inert. Two of these four ingredients have documented interactions with common medications:
- Ginkgo Biloba may increase the effect of anticoagulant and antiplatelet medication, including warfarin and aspirin therapy. Do not use if you take either.
- Panax Ginseng may interact with MAO inhibitors and stimulant-based medication.
Do not use this product if you take nitrates in any form, or if you are under 18. Speak to a doctor first if you have a cardiovascular condition, diabetes, or any chronic illness, or if you take prescription medication of any kind.
The full list of contraindications, dosage limits, and reported side effects is on the Medical Disclaimer. Read it before you order.
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