What 120 mg of Ginseng Is Up Against

Go down this panel with the federal pages open beside it and a pattern appears quickly. Ginkgo gets “no conclusive evidence that ginkgo is helpful for any health condition”. Saw palmetto gets a review that found little or no benefit. Hawthorn gets a sentence about conflicting evidence. Seven of the eleven botanicals get nothing at all, because no consumer summary exists. Our earlier post on that count laid it out.

Then there is Chinese ginseng. The National Center for Complementary and Integrative Health writes about Asian ginseng, and its sentence is the friendliest one anywhere on this panel: “Some research shows that taking oral Asian ginseng seems to improve sexual function in people with erectile dysfunction (ED).”

It is a careful sentence. It says “seems”. It is about people with a diagnosed condition, not about everybody. And it is a summary, which means a lot of study design has been folded away underneath it. This post unfolds it. What did those studies give people, for how long, and how big was the effect? Then, and only then, it holds the answer up against the number printed on the bottle.

One boundary first. The Protoflow label names no condition at all. It carries the usual disclaimer, a general caution line, and the words “optimal flow support” on the front. Erectile dysfunction comes into this post because that is the condition the ginseng trials were run on, not because the label claims anything about it. If that condition is the reason you are reading, it is a question for a clinician before it is a question for a supplement shelf.

This is a question people type into search engines in several forms — how much ginseng per day, ginseng dosage for men — and the honest answer depends entirely on which ginseng and for what purpose. For the erectile dysfunction literature, the answer can be read straight out of the abstracts.

The trials in the table are the ones the later reviews keep returning to, and all three used Korean red ginseng. The 2008 systematic review, whose authors include Edzard Ernst, defines it in its own abstract as unskinned Panax ginseng that is steamed or otherwise heated and then dried (PMID 18754850).

Two of the three abstracts state the amount, and it is large. Hong and colleagues gave 900 mg three times a day. de Andrade and colleagues gave 1,000 mg three times a day. Those are daily totals of 2,700 mg and 3,000 mg. The 1995 trial by Choi and colleagues, which compared ginseng with both a placebo and the drug trazodone, does not print its dose in the abstract, so this post does not guess one.

The results deserve a plain reading too. In the crossover trial, men scored higher on the International Index of Erectile Function while on ginseng, and 60 per cent answered that it improved their erections. In the 2007 trial, the five-item score went from 16.4 to 21.0 on ginseng and barely moved on placebo, and testosterone was the same in both groups. In the 1995 trial, frequency of intercourse, premature ejaculation and morning erections did not change in any group, while early detumescence, penile rigidity and girth, libido and satisfaction scored significantly better on ginseng. The authors were careful to say that no man was completely cured, only partly better.

Those are encouraging results from small, early trials. They are also what NCCIH’s sentence rests on. Notice, though, what the sentence does not say: it does not say anything about how much.

If you read only the abstracts of the three main reviews, you could come away with three different impressions of the same pile of trials. They are not contradicting each other so much as answering slightly different questions to different standards, and it is worth seeing how.

The 2008 review pooled six placebo-controlled trials and found that men on red ginseng were about two and a half times as likely to report a positive response. Its own authors called the evidence suggestive rather than convincing, because the trials were small and their quality was low on average. The 2018 review widened the frame to all herbal supplements for erectile dysfunction, pooled the ginseng trials, found a standardised improvement on the IIEF-5 questionnaire, and called the evidence encouraging. It also noted that adverse events did not differ significantly between placebo and treatment in the placebo-controlled trials.

The 2021 Cochrane review is the most cautious and, because of how Cochrane grades evidence, the most useful. It opens by saying that individual studies of ginseng are “mostly small, of uneven methodological quality and have unclear results”. It found the difference between ginseng and placebo to be statistically detectable but small: on the IIEF-15 erectile function domain, 3.52 points on a 1-to-30 scale, where the minimal clinically important difference it assumed was 4; on the IIEF-5, 2.39 points on a 1-to-25 scale, where it assumed 5. It also found that ginseng may improve men’s self-reported ability to have intercourse (risk ratio 2.55, 95% CI 1.76 to 3.69), on low-certainty evidence, and it found no trial comparing ginseng with the standard drugs for erectile dysfunction.

Ginseng side effects are a common search, so here is what the same sources say, compactly. The full treatment is on the side effects page.

NCCIH says short-term oral use of Asian ginseng in recommended amounts “appears to be safe for most people”, and that insomnia is “the herb’s most common side effect”. It adds that Asian ginseng “might lower blood sugar levels” and “may worsen autoimmune disorders and interfere with blood clotting”. In the trials, the Cochrane review found that ginseng may have little to no effect on adverse events compared with placebo, though its confidence interval was wide (risk ratio 1.45, 95% CI 0.69 to 3.03, low certainty). Wide means the trials were too small to rule out either a modest excess or a modest deficit.

The bleeding caution is the one specific to this bottle, because ginseng is not alone. Vitamin E and ginkgo each carry a published caution about anticoagulant drugs too, and all three sit in the same two-capsule serving. If you take a blood thinner or an antiplatelet drug, that combination is a conversation with a pharmacist before it is a purchase, which is exactly what the label’s own caution line tells you: consult a physician prior to use if you are currently taking any medication.