Yohimbine Side Effects and Warnings – Is it a Safe Supplement?

Yohimbine HCl is a powerful energizing and focussing naturally-occurring supplement. It is often used to support sexual vitality and is sometimes included in weight loss programs as an addition to a healthy diet and exercise routine. Although it is very popular, this supplement is not without a potential for adverse effects, especially at large serving sizes. The best way to avoid the risk of experiencing negative effects is to stick to the serving suggestion. In this article, we examine the most common Yohimbine side effects and take a closer look at potential warnings to bear in mind when taking this supplement.

Introduction – What is Yohimbine HCl?

Yohimbine HCl is a powerful naturally-occurring compound found in the bark of the evergreen Yohimbe tree (Pausinystalia johimbe), endemic to Central Africa. It is sometimes referred to as a ‘herbal remedy’ or Yohimbe bark and has a long history of use in traditional African medicine as a remedy for weight loss and for supporting men’s sexual health.[1]   In the United States, Yohimbine is approved by the FDA as a dietary supplement. It affects receptors in the brain called ‘alpha-2-adrenergic receptors’, which promotes an increase in dopamine, norepinephrine, and nitric oxide levels throughout the body.[2] Most people use Yohimbine for one of two benefits: either to help support a healthy metabolism (as part of a weight loss program), or to support sexual vitality. There is evidence to support both these claims.[3] For example, in 2006, a study examined this supplement’s effects on athletes (top-level soccer players), in terms of changes in body mass, muscle mass, performance indicators, and body fat percentage. Although there were no changes in the other outcomes, the group receiving Yohimbine recorded a noticeable reduction in both body fat percentage and total fat mass, significantly more than the placebo group.[4] In a 1998 clinical review, researchers systematically reviewed all the publications up to that date about this supplement’s effects on men’s sexual vitality, to try to determine both its efficacy and its safety. They found that, on average, Yohimbine HCl was significantly better than placebo at supporting men’s sexual health (with a 95% confidence interval), and that serious adverse reactions were both rare and reversible.[5]  

Yohimbine Side Effects - What are they?

Despite its popularity, it is important to stress that Yohimbine is a very powerful compound, and needs to be used responsibly. In its original use as a natural remedy, the traditional healer – ‘sangoma’ –  would crush the Yohimbine bark and add it to a mixture of a variety of different herbs and natural plant medicines. This mixture would then be used as a plant remedy. Today, the active compound in the Yohimbe bark (Yohimbine HCl) is sold as a 98+% pure powder. Its strength and potency are far superior to what was used in traditional medicine, years ago. According to WebMD.com, a good online source for information on supplements, the possible side effects from a typical Yohimbine HCl 98% supplement may include: “stomach upset, excitation, tremor, sleep problems, anxiety or agitation, high blood pressure, a racing heartbeat, dizziness, stomach problems, drooling, sinus pain, irritability, headache, frequent urination, bloating, rash, nausea, and vomiting.”[6] In 2010, a retrospective review was published, examining all the recorded cases of Yohimbine-related adverse effects, reported to the California Poison Control System. The study found that, for the seven-year period examined (2000 – 2006), a total of 238 cases were identified. This comes to around 34 per year. The adverse effects reported included (in order of prevalence):

• gastrointestinal effects
• tachycardia (abnormal heart rate)
• anxiety/agitation
• hypertension (high blood pressure).

  Importantly, the above study examined all cases where a “yohimbine-containing product” was ingested – meaning that someone could have been taking a ‘supplement stack’ (containing more than one compound, potentially causing dangerous interactions). In fact, just under 60% of the cases involved people using supplement stacks that included other ingredients, including stimulants like caffeine and ephedrine. 7 of the 238 cases were reported as ‘serious’.[7]    

Can You Overdose on Yohimbine HCl?

In short, yes. You can overdose on Yohimbine by consuming servings that are far larger than those recommended by experts and by reputable vendors. In 2011, a journal article published in the Journal of Dietary Supplements presented a case study of an otherwise healthy 24-year-old man, who had ingested a single 300mg serving of Yohimbine HCl (around 18x the maximum recommended serving size). He was admitted to hospital with high blood pressure and heart rate, as well as anxiety and agitation. At a follow-up examination, one week later, he was back to ‘healthy’ status.[8] In 2009, a man was admitted to hospital with severe neurotoxic effects, after consuming over 5000mg of Yohimbine. When he first arrived at the hospital, he had a blood serum concentration of 5,240 ng/mL Yohimbine. He experienced seizures, vomiting, and loss of consciousness, with significantly raised blood pressure and heart rate. The patient was treated with a number of medications. Twelve hours later, he had recovered and was alert and orientated.[9]   In 2013, a review was published examining two cases of fatal overdoses after Yohimbine use. In two separate cases, a 23-year-old bodybuilder and a 37-year-old man on a weight-loss program died after ingesting excessive amounts of Yohimbine. Their blood serum levels were 7’400 and 5’400 ng/mL, respectively, indicating that they consumed serving sizes similar to, or greater than, the above study.[10]  

Yohimbine Warnings

There are several warnings regarding Yohimbine interactions with medication and with other dietary supplements.

1. Yohimbine may increase the erectile effects of PDE-5 inhibitors like Viagra. Do not use these products together.[11]
2. Yohimbine may interact adversely with appetite-suppressing pharmaceuticals, including Sibutramine.[12]
3. Animal studies recorded interactions when used alongside stimulants like caffeine and ephedrine.[13] It may also interact with pharmaceuticals used for attention problems, like methylphenidate. Do not use these products together.[14]
4. Both alcohol and Yohimbine increase norepinephrine levels in the brain, and it is not recommended to consume these two substances at the same time.[15]

  IF YOU ARE TAKING ANY MEDICATION, PLEASE SPEAK TO YOUR DOCTOR BEFORE USING THIS SUPPLEMENT. Furthermore, this supplement may be unsafe for people with the following medical conditions:

• Bleeding conditions.
• Schizophrenia or psychosis
• Post-traumatic stress disorder
• Anxiety or depression
• Liver, kidney, or heart disease
• Diabetes
• Women who are pregnant or breastfeeding.

If you have any underlying medical conditions, please consult with your physician before using Yohimbine HCl supplements, or any supplement that contains Yohimbine. [7]

How to Use Yohimbine HCl Safely

Despite the possibility of experiencing adverse effects, many people enjoy the benefits of Yohimbine and manage to use this supplement safely and without any significant health issues. Its benefits for supporting sexual vitality improved energy levels, and when used in addition to a healthy diet and exercise program for fat loss are considered, by many people, to be great and worthwhile. The most important aspect of using this supplement safely is to stick to the recommended serving size. This recommendation is there for your own safety and is compiled by examining the available human studies on this supplement. Exceeding the serving suggestion will not improve Yohimbine’s benefits, but will certainly increase the risk of experiencing negative effects. For a 98% pure supplement, the recommended serving size is 1-4 servings of 4mg, taken no more than twice daily. Always start by using the smallest recommendation, and see how your body reacts. Some people are more tolerant and some people are more sensitive to different supplements. There is no way to know how you’ll feel before you’ve tried it, so always start with a smaller serving.   The same goes for supplement stacks that contain Yohimbine. These are certainly not all, by definition, unsafe. Again, what’s important is to stick to the recommended serving size. Be sure to read the ingredients list of the stack and before making a decision on how much to use. If the recommended serving size for the stack exceeds 16mg of Yohimbine, think twice before using.    

Is all Yohimbine the same?

A final, key aspect of Yohimbine safety is making sure that you purchase the supplement from a well-known and reputable vendor.  A 2015 study analysed 49 different brands of supplements selling Yohimbine, as pure or in a supplement stack. Of these, only 22% listed a specific quantity on the label. Of the 22% that listed an amount, most were labelled incorrectly, with the actual Yohimbine content differing from what was labelled by 77% less - 147% more. Furthermore, only 18% of the brands provided any information to consumers about the potential health effects of the supplement.[16] For the points above, it can be difficult to standardize a Yohimbine extract (for example, 1:4 extract) to an exact amount, as a result of variability in alkaloid concentrations in the plant. As a result, most reputable vendors use highly purified Yohimbine, to allow for standardization. It’s important to note that purification is not the same thing as adulteration. Purified products are, by many standards, safer than raw plant extracts, because the user is able to be aware of exactly what they’re consuming, and exactly how much to take. It just means that the product needs to be used responsibly.  

Conclusion - What are the key Yohimbine Side Effects?

In summary, Yohimbine HCl is a powerful naturally-occurring compound extracted from the bark of the Central African Yohimbe tree. Its benefits include an increase in energy and mental focus, support for sexual vitality, and support for a healthy metabolism. Some people use this supplement in addition to a healthy diet and exercise program, to assist with weight loss. This supplement is associated with a number of potential side effects, even at the recommended serving size. These can include nausea, upset stomach, dizziness, difficulty sleeping, irritability, rapid heart rate, high blood pressure, anxiety, rash, and frequent urination. In addition, excessively large servings are associated with a risk of overdose which can, in rare cases, be fatal. The most point of this article is to remind Yohimbine users to treat this supplement with care and to use responsibly. Many people around the world manage to use this great naturally-occurring compound to their benefit and do not experience adverse effects. It is important to start by using a smaller serving size, and seeing how your body responds. To avoid adverse effects, do not exceed the recommended serving suggestion. Furthermore, make sure you purchase this supplement from well-known vendors with a good reputation. <          

References:

[1] Kotta S, Ansari SH, Ali J. Exploring scientifically proven herbal aphrodisiacs. Pharmacognosy Reviews. 2013;7(13):1-10. [2] Millan MJ, Newman-Tancredi A, Audinot V, Cussac D, Lejeune F, Nicolas JP, Cogé F, Galizzi JP, Boutin JA, Rivet JM, Dekeyne A, Gobert A. Agonist and antagonist actions of yohimbine as compared to fluparoxan at alpha(2)-adrenergic receptors (AR)s, serotonin (5-HT)(1A), 5-HT(1B), 5-HT(1D) and dopamine D(2) and D(3) receptors. Significance for the modulation of frontocortical monoaminergic transmission and depressive states. Synapse. 2000 Feb;35(2):79-95. [3] Yohimbine. Examine.com, available online from https://examine.com/supplements/yohimbine/ [Accessed July 17^th, 2018] [4] Ostojic SM. Yohimbine: the effects on body composition and exercise performance in soccer players. Res Sports Med. 2006 Oct-Dec;14(4):289-99. [5] Ernst E, Pittler MH. Yohimbine for erectile dysfunction: a systematic review and meta-analysis of randomized clinical trials. J Urol. 1998 Feb;159(2):433-6. [6] Yohimbine. WebMD.com, available online from https://www.webmd.com/vitamins/ai/ingredientmono-759/yohimbe [Accessed July 17, 2018] [7] Kearney T, Tu N, Haller C. Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases. Ann Pharmacother. 2010 Jun;44(6):1022-9 [8] Cimolai N, Cimolai T. Yohimbine use for physical enhancement and its potential toxicity. J Diet Suppl. 2011 Dec;8(4):346-54. [9] Giampreti A, Lonati D, Locatelli C, Rocchi L, Campailla MT. Acute neurotoxicity after yohimbine ingestion by a body builder. Clin Toxicol (Phila). 2009 Sep;47(8):827-9 [10] Anderson C, Anderson D, Harre N, Wade N. Case study: two fatal case reports of acute yohimbine intoxication. J Anal Toxicol. 2013 Oct;37(8):611-4. [11] Senbel AM, Mostafa T. Yohimbine enhances the effect of sildenafil on erectile process in rats. Int J Impot Res. 2008 Jul-Aug;20(4):409-17. [12] Jordan J, Sharma AM. Potential for sibutramine-yohimbine interaction? Lancet. 2003 May 24;361(9371):1826. [13] Waluga M, Janusz M, Karpel E, Hartleb M, Nowak A. Cardiovascular effects of ephedrine, caffeine and yohimbine measured by thoracic electrical bioimpedance in obese women. Clin Physiol. 1998 Jan;18(1):69-76. [14] Gronier B. In vivo electrophysiological effects of methylphenidate in the prefrontal cortex: involvement of dopamine D1 and alpha 2 adrenergic receptors. Eur Neuropsychopharmacol. 2011 Feb;21(2):192-204. [15] Schuckit MA. Subjective responses to alcohol in sons of alcoholics and control subjects. Arch Gen Psychiatry. 1984 Sep;41(9):879-84. [16] Cohen PA, Wang YH, Maller G, DeSouza R, Khan IA. Pharmaceutical quantities of yohimbine found in dietary supplements in the USA. Drug Test Anal. 2016 Mar-Apr;8(3-4):357-69.