Pausnystalia Yohimbe
Also known as: Pausinystalia yohimbe, Corynanthe yohimbe, Yohimbine, Yohimbe, Yohimbe bark, Aphrodine, Corynine, Quebrachine
Overview
Yohimbe is an herbal supplement derived from the bark of the Pausinystalia yohimbe tree, native to West Africa. Traditionally, it has been used as an aphrodisiac and for various ailments like cough and fever. In modern Western medicine, its active alkaloid, yohimbine, is primarily utilized for treating erectile dysfunction (ED) and, to a lesser extent, for potential weight loss and athletic performance enhancement. Yohimbine functions pharmacologically as a selective alpha-2 adrenergic receptor antagonist. Research on yohimbine is moderate, with several randomized controlled trials (RCTs) and systematic reviews supporting its efficacy for ED. While evidence for ED treatment is robust, its effectiveness for other uses remains limited or inconclusive. The supplement is available in various forms, including raw bark and standardized yohimbine hydrochloride.
Benefits
The primary and most well-supported benefit of yohimbine is the treatment of erectile dysfunction (ED). Meta-analyses consistently show that yohimbine is significantly superior to placebo in improving erectile function. One meta-analysis reported an odds ratio (OR) of 3.85 (95% CI 2.22 to 6.67) favoring yohimbine over placebo for ED improvement. Another systematic review found yohimbine alone had an OR of 2.08 (95% CI 1.30–3.32, p=0.002) for erectile function improvement, with combined therapies showing even greater benefit (OR = 6.35, 95% CI 3.01–13.41, p<0.001). These findings indicate a moderate to strong effect size for ED treatment, particularly in men with organic ED, including diabetics. Secondary effects, such as modest weight loss and body composition changes, have been observed in animal studies, but human evidence is insufficient. Limited studies also suggest it may increase salivary flow and counteract drug-induced dry mouth (xerostomia). The benefits for ED are observed in short-term RCTs, but long-term efficacy and safety data are limited.
How it works
Yohimbine acts as a selective antagonist of alpha-2 adrenergic receptors. By blocking these receptors, it increases the activity of the sympathetic nervous system, leading to an elevated release of norepinephrine. This physiological response results in vasodilation and enhanced blood flow, particularly within penile tissues, which facilitates erection. Additionally, yohimbine influences central nervous system pathways involved in sexual arousal. Due to its sympathetic stimulation, yohimbine can also increase heart rate and blood pressure in some individuals. Its oral bioavailability is variable, and absorption can be influenced by the specific formulation and individual metabolic differences.
Side effects
Yohimbine is generally considered relatively safe at recommended doses, but it possesses a narrow therapeutic window, meaning the difference between an effective dose and a toxic dose is small. Common side effects, affecting more than 5% of users, include increased heart rate, elevated blood pressure, anxiety, headache, and dizziness. Less common side effects (1-5%) are nausea, tremors, and insomnia. Rare but severe adverse effects (<1%) can include severe hypertension, syncope (fainting), and psychosis. While serious adverse events are infrequent, they are typically reversible. Yohimbine has the potential for drug interactions, particularly with antihypertensives and other sympathomimetic agents. It is contraindicated in individuals with pre-existing cardiovascular disease, hypertension, anxiety disorders, or those taking monoamine oxidase inhibitors (MAOIs). Safety data for special populations, such as pregnant or breastfeeding women, are insufficient, and its use is not recommended in these groups.
Dosage
Effective doses of yohimbine hydrochloride in clinical trials for erectile dysfunction typically range from 5 to 20 mg daily. Optimal dosing can vary, with some studies utilizing 5.4 mg three times per day. The maximum safe dose has not been firmly established, but doses exceeding 20 mg per day significantly increase the risk of adverse effects. Yohimbine is often administered before sexual activity. It is crucial to note that while yohimbine hydrochloride is the standardized pharmaceutical form, raw yohimbe bark supplements can have highly variable yohimbine content, making accurate dosing unpredictable and potentially unsafe. Absorption may be enhanced when taken with food, though individual variability exists. No specific cofactors are required, but caution is advised when combining it with other stimulants.
FAQs
Is yohimbe/yohimbine effective for ED?
Yes, evidence from multiple studies supports moderate efficacy for improving erectile function, both as a standalone treatment and in combination with other therapies.
Is it safe?
Generally safe at recommended doses, but it can cause cardiovascular and central nervous system side effects. Medical supervision is recommended due to its narrow therapeutic window.
When should I take it?
It is typically taken before sexual activity, though specific dosing schedules can vary based on individual needs and product instructions.
Will it help with weight loss?
Human evidence for weight loss is insufficient. While some animal studies suggest modest effects, these findings have not been consistently replicated in humans.
Is raw yohimbe bark reliable?
No, the yohimbine content in raw yohimbe bark supplements is highly variable, making accurate and safe dosing unpredictable. Standardized yohimbine hydrochloride is preferred.
Research Sources
- https://www.auajournals.org/doi/10.1016/S0022-5347(01)63942-9 – This systematic review and meta-analysis of 7 randomized controlled trials concluded that yohimbine is significantly superior to placebo for improving erectile dysfunction, with an odds ratio of 3.85. It also noted that serious adverse events were rare, supporting its efficacy and relative safety for ED treatment.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9612744/ – This systematic review and meta-analysis of 8 RCTs found that yohimbine alone improved erectile function (OR 2.08) and that combined therapy with other supplements was even more effective (OR 6.35). The study highlights yohimbine's role in ED treatment, particularly when used in combination with other agents.
- https://www.drugs.com/npp/yohimbe.html – This source provides a comprehensive review of clinical data on yohimbine, detailing its mechanism of action, traditional uses, and documented side effects. It summarizes that yohimbine increases sympathetic activity and has been used for ED, orthostatic hypotension, and xerostomia, while also outlining its safety profile.
