Side Effects of Icariin

Icariin is a dietary supplement made from horny goat weed intended to treat impotence and increase athletic performance.

Despite the fact that the Icariin official website claims that there "has not yet been any officially documented undesirable side effects" from horny goat weed, the herb does pose a risk for side effects.


The Icariin website says that side effects are not possible if "the consumer is following correctly the dosage guidelines provided on the product they are using." However, there is no scientific evidence available to suggest that the dosage guidelines suggested in any type of horny goat weed supplement are safe for use, according to the Therapeutic Research Faculty.

Time Frame

Horny goat weed supplements are typically safe when taken in small doses for less than two years, according to the Therapeutic Research Faculty. This suggests that side effects from Icariin are more likely to develop the longer you take the supplement.

Types of Side Effects

Side effects of horny goat weed that are possible with long-term use or taking too much of the supplement include dizziness, vomiting, dry mouth, thirst, nosebleeds, muscle spasms and breathing problems.


When taken with drugs that have a thinning effect on the blood like heparin, warfarin or aspirin, horny goat weed has the potential to cause uncontrollable bleeding. Additionally, the combination of horny goat weed and hypertension medications like enalapril or valsartan poses a risk for dangerous drops in blood pressure levels.


Because of its potential to cause low blood pressure, it is not safe to take horny goat weed if you suffer from chronic hypotension.