I have read hundreds of scientific studies on yohimbine. I am a scientifically minded person, so I do recognize the value of properly conducted scientific trials. However, the picture painted by scientific studies is just as confusing as the picture based on anecdotal evidence.

Anecdotal evidence is that some people (including me) report a strong positive effect from yohimbine. I am not dysfunctional, just in an age bracket where one normally experiences a slow-down. I'm not happy with such a slow-down, and especially not with the prospects 10 or 20 years ahead. For me, yohimbine is a godsend. I have never been in better form than now (aged around 50), provided I can get hold of 10 to 20 milligrams of yohimbine.

That's my anecdotal evidence. Some of my friends claim they never felt anything from a single dose of yohimbine. I find that that hard to believe, and I suspect they used the wrong product, e.g. yohimbe bark with a very low percentage of yohimbine.

Unfortunately, with capsules that just contain yohimbe, the bark, you never know how much yohimbine you are getting. This could be between 0.01 and 10 mg per capsule. So some yohimbe capsules may contain 1000 times as much yohimbine as others.

Fort this reason, it is stupidity to buy a product of yohimbe, the bark, when one can obtain pure pharmaceutical yohimbine.

The scientific studies that I refer to below all used yohimbine, not yohimbe. The picture created by scientific trials is not coherent, though. Some studies come to the conclusion that yohimbine has no effect, even at doses much higher than I usually consume.

Other studies (I actually believe it's the majority) suggest that yohimbine is of some benefit, though the authors are typically less excited than I am.

A good number of studies have come to the conclusion that while yohimbine may do little to enhance sexual function, there are almost no side effects.

I, on the other hand, after an initial dose of about 10 milligrams, felt as if I'd pass out before getting down - though with a rock-hard erection.

That hasn't happened, and while yohimbe makes me restless, it doesn't raise my blood pressure... not when consumed in reasonable dosages. But I wouldn't want to try doses of up to 100 milligrams, or 30 milligrams for days on end.

Below are the abstracts of some scientific papers on yohimbine which I have seen over the years.

The Yohimbe Mensch*

(*I'm actually German)

Lack of scientific studies because yohimbine cannot be patented

36 milligram of yohimbine a day - bad result

30 milligram a day for 8 weeks - no serious side effects

Meta-analysis - the benefit outweight the risks

Test with 100 mg daily yohimbine

Up to 30 milligram a day - 3 of 11 men reporting strong positive effect

Yohimbine and apomorphine increase sexual appetite

Meta study: Yohimbine works as medication for diabetics with erectile dysfunction

Yohimbine allegedly has no measurable effect on healthy men, but some of those with problems report a strong positive effect

Meta study: Yohimbine works

100 mg yohimbine - not better than placebo, but anxiety as side effect

30 milligram yohimbine - significantly better than placebo

15 mg of yohimbine - not better than placebo for patient with organic erectile dysfunction

American Urological Association: yohimbine only has marginal efficacy, not justified for erectile dysfunction based on organic problems

Before Viagra, pills were not effective to treat erectile dysfunction

36 mg yohimbine per day not better than placebo