Acid is a freaky drug; it can make you feel like you’re a kid again, or trap you in a real-life horror movie. So when you buy it off the internet, there’s understandably some trepidation: is this going to make me completely lose my mind forever?

A group calling itself The LSD Avengers arose to answer that question for users of the Silk Road, the deep-web black market that sold drugs and other contraband until police took it down earlier this month. After a slew of scams on the site and reports of dubious acid, the Avengers began ordering from different vendors on the site, subjecting their wares to a chemical reagent test and a gas chromatography mass-spectrometry machine. If the drug was in fact LSD, the Avengers consumed it and posted Yelp-like reviews.

"When the Silk Road started the majority of LSD was actually a variety of research chemicals," says an individual who identified himself or herself as "the Official Spokesperson of the LSD Avengers which is a volunteer-based infrastructure in an anonymous libertarian marketplace." "Due to the lack of information on the longterm effects of these drugs, we wanted to make efforts to protect our curious brothers and sisters."

The Avengers also factored packaging, general cautiousness, shipping time, and customer service into their evaluations. They posted their last review on October 1st, the day before Silk Road was seized by the authorities. They had reviewed 60 vendors, include 14 "star" sellers, 19 "OK" sellers, and 27 "bad" sellers.

Some typical reviews:

3JANE - Canada to International. Known fondly as the Queen of SR. Quality LSD with appropriate dosages advertised. Extreme Ninja-Spy stealth shipping with friendly communication.HAIZENBERG - Czech to International. Extremely friendly and personable customer service with consistent product and regular stock. Currently selling: Hofmann, Dancing Bears and Strawberrys (advertising 110ug) Trip Test Hofmann: ~100ugMARIJUANAISMYMUSE/GOINGPOSTAL - Canada to International. Vials and some other shit. Last time we tried to test them they packaged the acid so badly that it was seized in transit. A few past selective scamming claims from trusted members, so be absolutely sure to read their FE [finalize early] and refund policies. We still don't know the quality/consistency of the acid because it was taken by LE [law enforcement] and will not be able to test them for safety reasonsThe Avengers were looking for sellers who stole customers’ money or tried to pawn blank pieces of paper. More often, however, they were looking to root out research chemicals that were being sold as acid. Those include DOx compounds (synthetic amphetamines), the 25x-NBOMe or 25x family (synthetic psychedelics that have only been around for the past few years), and ergoloid (a compound invented by the creator of LSD and used to treat dementia). These chemicals aren’t more dangerous than acid; they just have slightly different effects. They are also newer, so their cumulative effects are not well understood.

While research chemicals have their fans, the Avengers were interested in the original stuff: lysergic acid diethylamide, a powerful psychedelic derived from a fungi that grows on rye. "LSD is a beautiful substance that is more special to us than other classic psychedelics," the spokesperson says.

"Once the chem test checked out, we would have somebody test it for potency," the spokesperson says. "Or we'd send it to the lab. So somebody in the Avengers family has tried each batch we approve."

The Avengers were in search of the "Holy Grail" of LSD, known as "needlepoint acid," which has a high purity. "We saw a little bit of it," the spokesperson says in an email. "In fact, it was starting to come around A LOT literally a week before Silk Road was taken."

The semi-professionalism of the Avengers reflects the needs of the clientele on Silk Road, which had become a hub for serious recreational drug users. The Avengers and their fans treated the site like a foodie at a gourmet tradeshow.

Silk Road seemed to be a safe place to buy really good drugs, if you knew what you were doing. The prices might be higher than what you’d pay on the street, but dealers on Silk Road were held somewhat accountable by the community. The seller-rating system built into the site, along with efforts by unofficial groups like the Avengers, created a meritocracy that rewarded dealers who sold good stuff (with the exception of the infamous tony76 fraud, in which a well-reputed seller took a bulk of orders and disappeared). And when law enforcement tested the wares on Silk Road, police found they typically had a high purity level of the drug advertised.

The Avengers have retired now that Silk Road has been shut down, although there is already a successor on Black Market Reloaded, one of the newer virtual black markets taking in Silk Road refugees. Other similar review groups existed for ecstasy and the hallucinogen DMT, part of a self-regulating community amid the anarchy of the digital black markets.

"We had a good ride," the LSD Avengers spokesperson says. "We are pretty tired now and had our fun."