The FDA says the ingredient can cause dangerous drops in blood pressure.
TimeOut Capsules are marketed as a dietary supplement for sexual enhancement.
The FDA analyzed the product, and determined it contains hydroxythiohomosildenafil.
That's a chemical similar to sildenafil, the active ingredient in Viagra. Like sildenafil, this chemical may interact with prescription drugs such as nitrates, including nitroglycerin, and cause dangerously low blood pressure.
The blood pressure drop can deprive the brain of a sufficient blood supply, leading to dizziness or lightheadedness.
TimeOut, which is sold on internet sites, in 2,500 milligram capsules, is labeled as "100% natural" and consumers may mistakenly assume the product is harmless and poses no health risk.
The FDA says that to date, there haven't been any adverse events reported which are linked to the product.
But it urges anyone who has timeOut Capsules are urged to stop taking them immediately.
And if you have had an adverse reaction, report it to the FDA's MedWatch program at 800-FDA-1088 or online at www.fda.gov/medwatch/report.htm.
In recent years, federal drug watchdogs have found many suplements sold for sexual enhancement are adulterated with ingredients that are in prescription drugs, or are variations of those ingredients.