In the flurry of research following the discovery of LSD, Albert Hofmann found another chemical with similar effects at similar dosage and filed it away in Sandoz's journals. That chemical was ALD-52, also known as 1-Acetyl-N,N-diethyllysergamide. During Sandoz's testing of the chemical, some subjective human studies were done in which ALD-52 was reported to be as effective as LSD, without the anxiety, tenseness, and other problems inherent to it. Twenty years later, in the middle 1960's, ALD-52 was rediscovered and investigated by the budding psychedelic community.

A famous historical brand of ALD-52 tabs named Orange Sunshine was popular during the Summer of Love, although it was sold on the street as plain LSD. One of the labs manufacturing it was busted, but claimed to not be breaking the law due to making ALD-52 instead of LSD. In what was probably the first drug analogue trial, their defense was shot down on the grounds that ALD-52 decomposed into LSD -- so the tabs actually did contain illegal product -- and that LSD was a necessary precursor to ALD-52. They were right on the first account, as ALD-52 combines with the water in the air to produce LSD. On the second count they were mistaken, as the country's underground chemists had figured out how to change the reaction's steps so LSD wasn't present at any stage of manufacture.

Interestingly, most of acid's reputation for being impure can be traced back to Orange Sunshine tabs. Since they were widely known as good, labs all over the world started making knock-off tabs that looked like the real thing, but contained plain-jane LSD, or often nothing at all, or in one case strychnine. With all of these being unlike the much-loved Sunshine, the market became confused and it was impossible to know whether a given dose would be real or not. These impurity problems later (1975) caused Timothy Leary to actually recommend against taking acid, because it was so difficult to trust.

Even today people complain about "impure" acid, even when what they're taking (liquid or windowpane) couldn't possibly contain strychnine, amphetamines, or anything else that isn't effective inside of the microgram range. There's also a notion of "really good acid," the kind that doesn't make you feel jittery or paranoid. Well, here's news: that's ALD-52 you're thinking of, not LSD-25. Anxiety is built into LSD's effect profile, impossible to get out no matter how pure the product is -- your joints don't ache from strychnine kids, they ache from acid.

Also, some brands of acid feeling different from one another is due to conversion from ALD-52 into LSD. Since they're both psychoactive in the same dosage, "strength" won't change drastically with degradation, while their effect will. Unless what you're taking is really DOB, which can fit on a blotter in low doses -- then it will be way different.