Delta-9-THC, the main drug in cannabis plants that gets people high, can also be a potent medicine. It can treat extreme nausea and stimulate appetite, which is especially helpful for people who have HIV or are going through chemotherapy. A synthetic version of THC, called Dronabinol, has been used to treat these conditions since the 1980s, although some people prefer their THC to come from the plant itself. But while marijuana is a relatively mild drug with few side effects — at least, compared to alcohol or tobacco — too much Delta-9-THC has its downsides. It can sometimes spark paranoia and anxiety or trigger dizziness and headaches. And it’s worth noting that much of the cannabis sold legally in the U.S. contains a high THC concentration. That’s why many cannabis consumers are turning to an obscure analogue of Delta-9-THC called Delta-8-THC. The difference between Delta-8 and Delta-9 is subtle: Both will get you stoned, but the former is about half as potent as the latter. Many people claim that Delta-8 is a smoother, less anxious psychoactive experience than the more familiar Delta-9. It also seems to have additional medicinal effects than regular THC, such as better pain relief, but these claims have yet to be weighed out in clinical trials. Based on these anecdotal reports, Delta-8 is quickly becoming a trendy new cannabis product, appearing in products like vape cartridges, soft drinks, gummies and tinctures. The rise in popularity mirrors the CBD (cannabidiol) craze before it and, like with CBD, there still isn’t a lot of quality control for products or evidence to back up anecdotal accounts. Many of the same positive claims are made about Delta-8 products — though scientists have yet to study their effects in depth. The cannabis plant is essentially a factory for dozens of different compounds called cannabinoids. The two most popular are also the most abundant: Delta-9-THC and CBD. But the plant also makes many other so-called minor cannabinoids, including CBG, CBN, THCV and, of course, Delta-8-THC. Most cannabis plants produce very small levels of Delta-8, so to get a usable amount takes a lot of processing and refinement. However, Delta-8 is more shelf-stable than Delta-9, which could make it a better option for prescription drugs. The main difference between Delta-8 and Delta-9 comes down to the location of a specific bond between two of the atoms that make up each THC molecule. “Delta-8 has the double bond on the 8th carbon in the chain, while Delta-9 has the double bond on the 9th carbon in the chain,” explains Christian Peterson, the co-founder and COO of Wunder, a cannabis beverage company based in San Francisco. Wunder sells a line of Delta-8-infused products that mix Delta-8, Delta-9 and CBD as a replacement for alcohol.