Introduction

Technically, it is true to say that yohimbe comes from the African savannah and has been used for a very long time as a herbal aphrodisiac and aid for erectile dysfunction (which all sounds very exotic and earthy). However, that would only be part of the story and not the full story.

Yohimbe has a dark side that should also be spoken about. Yohimbe is also known as ‘yo yo’ and is a street drug used as a hallucinogen, aphrodisiac and weight loss agent. Unfortunately, both yohimbe and ‘yo yo’ have been associated with a number of fatalities.

In this article, we will look at the science behind the two faces of this compound – the herbal remedy (yohimbe) and the street drug of abuse (yo yo).

What Is Yohimbe?

More than 5400 plant species are used in traditional medicine in Africa but less than 10% of these plants have been developed for commercial use. Yohimbe is one of that 10% and is commercially traded (legally and illegally) worldwide.

Firstly, to the nomenclature:

  • johimbe is the plant name
  • yohimbe is the popular name
  • yo yo is the street name and
  • yohimbine is the active component.

Yohimbe comes from the evergreen African Pausinystalia yohimbe tree which belongs to the Rubiaceae family.
Owing to the popularity of yohimbe, the Pausinystalia tree is at risk of extinction.

Yohimbe contains about 6% alkaloids including: corynanthine, rauwolscine, ajmalicine and yohimbine. The indole alkaloid, yohimbine represents about 15% of the total alkaloid content and is the most bioactive ingredient. Levels of yohimbine in the bark extract vary from tree to tree and are often very low. Both bark extract and a standardized yohimbine hydrochloirde salt formulation are available for sale.

Yohimbe has been used in traditional medicine as an aphrodisiac and erectile function aid for a very long time. It has been called an ‘orphan drug’ but this is totally incorrect. Orphan drugs are used to treat orphan diseases which are rare medical conditions. Erectile dysfunction could not be considered under any circumstances to be a rare medical condition.

Yohimbe is a potent alpha 2 antagonist and a weak alpha 1 antagonist. It blocks pre and post synaptic receptors and causes a release of noradrenaline and dopamine. It is usually prescribed at a dose of 5 -10 mg and the dose is then titrated based on the response and tolerability. There are 396 yohimbe products for sale on Amazon and retail for approximately $0.12 for 500mg.

Is There Any Research?

There are 49 publications and 2 clinical trials on yohimbe, yohimbine and Pausinystalia. To put this into context, Viagra has 5000 publications and 80 clinical trials.

Does Yohimbe Treat Erectile Dysfunction?

There are a number of studies which address this question.

A total of 63 patients who had psychogenic impotence were randomized to either placebo or yohimbine (15 mg per day orally) plus trazodone (50 mg per day orally) used together for 8 weeks. The study also had a cross-over component in that patients who initially received the placebo subsequently took yohimbine plus trazadone for 8 weeks (An unusual study design).

Erectile function, ejaculation, interest in sex, and sexual thoughts were investigated at the end of drug treatment and at 3- and 6-month follow-up visits . Results were significantly better for the predetermined outcomes in the active treatment arm of the study and was maintained in 50% of the patients for up to 6 months.

A study of 18 men in Florida with non-psychogenic erectile dysfuntion who were treated with yohimbine showed that 9 men (50%) were successful in completing intercourse in more than 75% of attempts .

A 2011 review of complimentary and alternative medicine for erectile dysfunction for older men and women interrogated 6 electronic databases to identify all relevant systematic reviews . Only four systematic reviews met the inclusion criteria as set out by the team of British investigators. The conclusion of the review was that ‘cautiously positive results were drawn for yohimbe and ginseng as treatment options of erectile dysfunction’.

Bottom Line

A very small number of studies suggest that yohimbe can help erectile dysfunction. However, before you rush out to buy some yohimbe, please read the safety section to get the full story.

Does It Help Depression Symptoms?

There are no studies linking yohimbe to mood disorders.

Botton Line

 Yohimbe does not help depression symptoms.

Does It Treat Blood Pressure Problems?

Technically, yohimbe can exert influences on blood pressure in view of its effects on the alpha adrenergic system. Yohimbe acts by raising BP. However, it would be completely daft to use yohimbe for this indication as it would be an extremely blunt instrument (pharmacologically speaking). That might be why there are no studies looking at yohimbe for hypotension management.

Bottom Line

 Yohimbe is neither used nor studied as a BP agent.

Does It Lower Side Effects of Some Medications?

The things that some people make up out of the air just to have something to say. Some really unprofessional bloggers claim that yohimbe lowers the side effects of medications. Here is their logic:

  • antidepressants can cause erectile dysfunction as a side effect
  • yohimbe helps sexual dysfunction
  • therefore, yohimbe helps lower the side effects of some medication.

This is technically true but is just another way of saying that yohimbe can help sexual dysfunction.

In medicine, when we talk about lowering side effects of medications, we mean something different like when we co-prescribe vitamin B6 with TB therapy to reduce peripheral neuropathy which is a studied, proven strategy.

Bottom Line

There are no studies looking at yohimbe as a strategy to minimise side effects of medications.

Does It Help With Weight Loss?

There is only one result for a PubMed search for ‘yohimbe and weight loss’. A 2005 paper from Plymouth looked at the relationship between yohimbe and weight loss. Literature searches were conducted on Medline, Embase, Amed and The Cochrane Library. Data were also requested from the spontaneous reporting scheme of the World Health Organization. The team also hand-searched relevant medical journals and their own files.

There were no restrictions regarding the language of publication. This is an interesting approach. On the plus side, this trawl of the literature yielded more results than a traditional PubMed search. On the negative, side, it likely yielded some bottom feeders and by that I mean poor quality studies that were not good enough to be published as full papers. (In the publish or perish world of medicine, young doctors end up doing lots of mediocre research that they can turn around fast in order to have some type of research on their CV).

Overall, the review found that garcinia cambogia and yerba mate merit further investigation as potential weight loss agents.

Bottom Line

There are no quality studies linking yohimbe to weight loss.

Does It Help Increase Alertness?

As we will see in the next section, yohimbe can cause insomnia and anxiety but does not increase alertness in any meaningful useable way.

Bottom Line

 There are no clinically useful links between yohimbe and alertness.

Is Yohimbe (and or Supplementation) Safe?

Over 550 different brands of yohimbe are available in the USA where it is licensed for the management of erectile dysfunction. However, yohimbe comes with the risk of poor quality control and potentially life threatening toxicity.

Researchers from Harvard studied 49 brands of supplements which were labelled as containing yohimbe or yohimbine from 7 major retailers in the USA . Only 4.1% provided the consumer with accurate information about the quantity of yohimbine and the possible side effects. A total of 39% of the products did not contain other alkaloids such as rauwolscine or coryhanthine which would suggest that the extract came from a highly processed plant extract or was synthetic in origin.

An average oral dose of yohimbe produces blood level of 40-400ng/ml. Overdoses with blood loveless high as 7000ng/ml have been reported. The California Poison Control Center has linked 130 hospitalisations to yohimbe between 2000 and 2006.

In 1997, the FDA issued a warning against the combination of yohimbine and caffeine with ephedrine following a number of deaths .

A 2013 paper from the LA coroners court describe two fatalities associated with yohimbe. The first case related to a 23 year old body builder who was taking supplements and the second related to a 37 year old who was trying to lose weight and was taking mail order dietary supplements containing yohimbe.

The following is not for the squeamish. Don’t say I didn’t warn you.

A 42 year old man with HIV infection presented to the emergency department at a Veterans Administration Hospital with a sustained erection for over 20 hours. Despite what teenage boys might think, there is nothing good about a 20 hour erection. In fact, this is a medical emergency known as priapism. Bloods drawn from the penis (yes that’s what I said) showed a metabolic acidosis constant with penile ischemia (yes penile ischemia). Phenylephrine was injected into the area which ‘detumesced’ the area. I will leave you to figure out what detumesced means. However the erection returned (not funny at all).

Three more phenylephrine injection were given but these too were unsuccessful. The patient was brought to the operating room for a cavernosal shunt (that means a shunt in the penile blood vessels). What could make that ordeal worth while.

Another case report describes adverse reactions to yohimbe in a teenage girl. Following the ingestion of an alleged aphrodisiac known as yo-yo,  the 16-year-old girl experienced an acute dissociative reaction accompanied by weakness, paresthesias, and incoordination.

Subsequent symptoms included anxiety, headache, nausea, palpitations, and chest pain. Hypertension, tachycardia, tachypnea, diaphoresis, pallor, tremors, and an erythematous rash were noted on physical examination. Fortunately, the symptoms resolved spontaneously but lasted approximately 36 hours. The ingested substance was identified as yohimbine.

Conclusions

It has been said that ‘any discussion of the use of P johimbe bark for sexual enhancement begins and ends in folklore’ (11). In fact, that is not the case as there are some small studies that suggest that yohimbe helps with erectile dysfunction. However it would be so unfair and unsafe to elevate yohimbe out of folklore status and imply that it is a reasonable alternative to licensed prescription medication. Here’ s why.

Efficacy is just not enough. Houston, we have a problem. It is unusual to find a herbal medicine where the data on side effects (including deaths) significantly outweighs the data on benefits.

Yohimbe comes with the problems of poor quality control and potentially life threatening toxicity which makes this a very poor choice for any modest gains that it might offer (yes, even allowing for the fact that sex is one of the key human drives). There are safer and better studied alternatives.