While marijuana is becoming legalized in more and more areas, other recreational drugs are starting to come under increased scrutiny.

Following pressure from Advisory Council on the Misuse of Drugs (ACMD), U.K. parliament has decided to review the use of “poppers,” which is a blanket term for various forms of alkyl nitrites.

The ban on the popular recreational drugs begins in April, but it could be lifted as early as July, when medical evidence is reviewed. The ACMD has said poppers were “not seen to be capable of having harmful effects sufficient to constitute a societal problem.”

In the U.K., it’s been illegal to market and sell poppers for human use since 1968, but marketing loopholes made them available over the counter and on the Internet.

During debates of how poppers should be regulated, Crispin Blunt — a member of Parliament, and uncle of actress Emily Blunt — made headlines when he admitted to being a popper user.

Typically thought of as a “gay drug” because of their historical place in LGBT culture, poppers have found their place in club culture — from 1970s discos to raves in the 1990s — crossing all racial and sexual boundaries. Their use sharply rose between 2000 and 2010 in France, becoming the second most popular drug of choice by teenagers, behind marijuana. While banned for a time, France opted for warnings on packaging rather than a ban.

In the United States, amyl nitrite was first listed as a prescription drug, but that was lifted in 1960 after the U.S. Food and Drug Administration (FDA) determined them to be safe. After an increase in recreational use, they were later banned for inhalant use by the Anti-Drug Abuse Act of 1988.

They’re banned completely in Canada.

The term “poppers” stems from their earlier packaging. They used to be sold in glass vials and made a popping noise when crushed.

Today, they’re sold in sex and leather shops in bottles from 10 to 30 milliliters.

Because of their distinctive fruity, sweet aroma, they are often sold as air fresheners. In other countries like the United States, they’re also sold and marketed as video head cleaners, leather cleaner, and nail polish remover.

And, yes, they have other uses.

When inhaled, poppers cause vasodilation — dilation of the blood vessels, which causes your blood pressure to lower.

When inhaled, they can produce a slight euphoric effect for several minutes, loosening a person’s inhibitions and increasing sexual pleasure. It’s used in preparation for sex because it relaxes the smooth muscles that surround blood vessels.

While the risk of dependence is low, poppers are not without their risks. The potential adverse effects associated with poppers can vary from mild allergic reactions to life-threatening methemoglobinemia, which is when there are abnormal amounts of hemoglobin in the blood.

One major concern is how poppers interact with other drugs. For example, Viagra, Cialis, and other erectile drugs, when coupled with poppers, can create an unsafe drop in blood pressure.

As poppers can reduce inhibitions like other drugs, the propensity toward unsafe sex is another potential concern.

Poppers and HIV/AIDS

The notion that poppers can increase your chances of HIV infection has been popular since the 1980s, when the HIV/AIDS epidemic came under the national spotlight. Poppers are popular in the gay community, but most research agrees that there is no traceable link between poppers and HIV infection.

Other research suggests that substance use in general — whether poppers, cocaine, or other club drugs — increases the risk of unprotected sex, and thus the transmission of sexually transmitted diseases. The research, however, was unable to show poppers were more risky than other drugs.

If you have a heart condition or blood pressure issues, consult with your doctor about potential dangers you may face if you use poppers or other recreational drugs. And always practice safe sex.