Yohimbine, also called quebrachine, is an indole alkaloid derived from the bark of the African tree Pausinystalia yohimbe tree. It is a veterinary medication used to reverse sedation in animals such as dogs and deer. Traditionally used as an aphrodisiac and stimulant, yohimbine primarily functions as an α2-adrenergic antagonist, blocking these receptors to enhance sympathetic nervous system activity, which may result in increased blood flow.
BRAND NAMES
Yocon- available in oral tablet.
Yoman- Take the capsules with warm milk or water following dinner.
Yohimex- available in oral tablet or capsule form. It is consumed by mouth with a glass of water.
Erex- Tablets, capsules, and drops.
MECHANISM OF ACTION
Yohimbine mainly functions as an alpha-2 (α2) adrenergic receptor blocker. By blocking the negative feedback mechanism on norepinephrine (NE) release, it increases sympathetic nervous system activity and promotes the release of both epinephrine and norepinephrine throughout the body.
PHARMACOKINETICS
Absorption
Yohimbine is rapidly absorbed after oral administration, but its bioavailability varies significantly among individuals, from 10% to 90%. Several factors, including food consumption, individual genetics, and the supplement's purity, influence its absorption.
Distribution
The bioavailability shows considerable variation, ranging between 7% and 87%, with a mean of 33%.
Metabolism
In the liver, yohimbine is metabolized by cytochrome P450 enzymes primarily CYP2D6 and CYP3A4, into 11-hydroxy-yohimbine and 10-hydroxy-yohimbine, which are then excreted by the kidneys. This process exhibits significant variability between individuals because of genetic polymorphisms in these CYP enzymes, causing some people to be "poor metabolizers" who may experience stronger or longer-lasting effects.
Excretion
Less than 1% of the yohimbine dose administered is eliminated unchanged in the urine. The vast majority is cleared through metabolism in the liver before being excreted as inactive metabolites.
PHARMACODYNAMICS
Yohimbine is a central and peripheral alpha-2 adrenergic receptor antagonist that increases sympathetic nervous system activity by boosting norepinephrine release. This antagonism disrupts a normal negative feedback loop, causing a cascade of downstream effects on the cardiovascular, metabolic, and central nervous systems.
ADMINISTRATION
The total daily dose is commonly broken up into two to four smaller doses taken at intervals throughout the day. For instance, a person weighing 150 lbs (68 kg) might take 7 mg twice a day to achieve a total daily dose of 14 mg. Supplementation is most effective when taken between meals or during short-term fasting.
DOSAGE AND STRENGTH
yocon-0.5-1 tablet/caplet TID.5.4 mg orally 3 times a day.
yoman- compounding powder, oral tablet. Take 2 Capsules Daily Preferable with warm milk or water after dinner.
yohimex-5.4 mg orally 3 times a day.
erex-1 capsule twice a day.
DRUG INTERACTIONS
Yohimbine can interact seriously with many medications and should be used only under the guidance of a healthcare professional. Interactions range from minor effects to life-threatening reactions, particularly involving drugs that affect blood pressure, heart rate, or the central nervous system.
FOOD INTERACTIONS
Yohimbine can interact significantly with foods high in tyramine—such as aged cheeses, red wine, and liver—potentially causing dangerously elevated blood pressure. It may also interact with certain antidepressants, other dietary supplements, and alcohol. These potential interactions should be discussed with a healthcare provider due to associated risks. Since yohimbine is not found naturally in foods, these interactions occur specifically between the supplement and certain foods or substances.
CONTRAINDICATIONS
Yohimbine has numerous contraindications and is considered potentially unsafe due to its stimulant effects and serious drug interactions. It is banned in many countries due to a lack of sufficient safety research and quality control.
SIDE EFFECTS
Increased blood pressure, accelerated heart rate (tachycardia), and noticeable heart palpitations.
Anxiety, nervousness, irritability, dizziness, headaches, and tremors.
Nausea and stomach problems.
Sweating and skin flushing.
Kidney problems.
Neurological problems.
Severe cardiovascular problems.
OVER DOSE
Anxiety, irritability, and restlessness.
Dizziness and confusion.
Tremors or shaking.
Seizures.
Psychosis or manic reactions.
Increased heart rate.
Irregular heart rhythm.
High blood pressure (hypertension).
Heart attack.
TOXICITY
Yohimbine toxicity, resulting from an overdose, is a serious and potentially fatal condition caused by excessive sympathetic nervous system stimulation. The severity of the reaction depends on the dose, individual sensitivity, and health status. Because over-the-counter yohimbine supplements are often inaccurately labeled, the risk of accidental overdose is significant.
