Watch out, Israeli customers: That coffee you bought may be a lot stronger than you think!

Israel’s Health Ministry is warning people that products like “Magic Power Coffee” contain counterfeit Viagra. This powdered instant coffee drink, as well as others, are touted by marketers as natural alternatives to the erectile dysfunction drug. However, lab tests performed by the Health Ministry discovered that they actually contained the same chemical substance that is found in Viagra.

Viagra is a controlled substance in Israel, and may only be obtained by a doctor’s prescription. Channel 2 News reports that the company marketing “Magic Power Coffee” lists on its website the product’s active ingredients — but that the Viagra-like substance is not mentioned. Furthermore, the website claims that the use of the product is authorized by the Health Ministry.

Back in 2010, the Food and Drug Administration put out an alert about “Magic Power Coffee.” It warned “consumers not to buy or use Magic Power Coffee after it was found to contain undeclared hydroxythiohomosildenafil, which is an unauthorized substance similar to sildenafil and may pose similar health risks. Sildenafil is a prescription drug used to treat erectile dysfunction and should only be taken under the supervision of a health care practitioner.”

Looks like Israelis will still be able to use coffee as a stimulant — just not this particular brand…and not for this particular purpose.