Delta-8 vs. Delta-9: Comparing Types of THC

A farmer examines the new harvest of a hemp field. SasinT Gallery / Getty Images

"Delta 8" has become a bit of a buzzword in the cannabis industry and the community health sphere. But what exactly is delta-8, and how is it different from "regular" cannabis?

Here, we'll explore more about THC and break down delta-8 vs. delta-9.

What Is Delta-9?

Delta-9-tetrahydrocannabinol (delta-9-THC) is a psychoactive compound produced by the Cannabis sativa plant when heated. The cannabis plant can produce hundreds of psychoactive chemicals — chemicals that can cross the blood-brain barrier and produce psychological effects — the most famous of which is tetrahydrocannabinol (THC).

THC comes in different forms known as isomers. Isomers are compounds with the same molecular formula — in the case of THC, C₂₁H₃₀O — but different arrangements of atoms. The different arrangements of atoms can cause isomers to behave differently.

When people talk about THC, they're usually referring to delta-9-THC. Delta-9-THC is the most-studied THC isomer, and pure delta-9-THC for different medical conditions can be prescribed by doctors as dronabinol when encapsulated with sesame oil. Legal medical cannabis is used for chronic pain relief, appetite stimulation and nausea relief.

What Is Delta-8?

Delta-8 THC is a double-bond isomer of tetrahydrocannabinol. Compared to delta-9-THC, relatively little is known about delta-8, and it has not been evaluated by the United States Food and Drug Administration (FDA).

Despite the lack of research surrounding the safety of delta-8, the drug is fairly popular. That's because of a legal loophole in the 2018 U.S. Farm Bill, also known as the Agriculture Improvement Act. The farm bill legalized hemp, a nonpsychoactive form of the cannabis plant used to produce cannabidiol (CBD), cloth and paper.

The Farm Bill defined hemp as containing less than 0.3 percent delta-9-THC, but there was no mention of how much delta-8-THC (or other cannabinoids) hemp could contain. Because of this, people have been able to extract psychoactive amounts of delta-8 THC from nonpsychoactive hemp-derived products.

Is Delta-8 Safe?

The safety of delta-8-THC is unknown used. According to the FDA, from the time delta-8 was added to the National Poison Control Center's database in January 2021 to February 2022, there were 2,362 cases of delta-8 exposure, 70 percent of which required medical attention.

Because delta-8 is unregulated, consumers typically don't know how much THC these products actually contain — or if they contain other, potentially harmful chemicals. Delta-8 can cause adverse events for children and pets. (Approximately 41 percent of poison control cases for delta-8 involved minors.)

Despite the lack of regulation and empirical evidence surrounding delta-8, the drug is very popular, especially among teens. A 2023 survey found that 11.4 percent of U.S. 12th-grade students had used delta-8.

What's the Difference Between Delta-8 and Delta-9?

Although delta-8 and delta-9 are both forms of THC and have psychoactive effects, there are a few important differences:

Chemical structure: Delta-8 and delta-9 are isomers, which means they have different chemical structures. Delta-8 has a double bond between the eighth and ninth carbons; delta-9 has a double bond between the ninth and 10th. Other than that, they are chemically the same.
Medical authorization: Delta-9-THC is approved for medical use under dronabinol. Its medical benefits have been proven for conditions including sleep disorders, HIV/AIDS, and cancer. However, more research is needed to establish the health benefits of delta-8.
Psychoactive effects: Both delta-8 and delta-9 have psychoactive and intoxicating effects when consumed in concentrated amounts, but some users report that delta-8 can be milder. According to a 2022 article published in the Journal of Cannabis Research, users found delta-8 more pleasant than delta-9. However, public health officials warn that products labeled delta-8 may contain other chemicals.
Extraction process: Delta-8 products are typically manufactured from products like legal CBD, which contains very low levels of THC. A product labeled delta-8 could contain other cannabinoids or even heavy metals, the New York Times reports.
Legality: Although some consider delta-8 "technically legal" because the Farm Bill focuses explicitly on delta-9, there are some states where delta-8 products are illegal, while recreational cannabis and delta-9-THC are legal, such as Colorado and New York.