Types of THC: Delta-9, Delta-8, THCA, THCV and More

TABLE OF CONTENTS

The main types of THC are delta-9, delta-8, delta-10, THCA, THCV, THCP and the lab-made THC-O acetate. THCV is covered in more detail in our guide to what early research shows about THCV. Only delta-9 THC, as the prescription drug dronabinol, has FDA-approved uses, for chemotherapy nausea and appetite loss in AIDS; the others rest on user reports or early lab, animal and small pilot studies.

The letters THC, short for tetrahydrocannabinol, appear in the names of several related compounds, and each has its own effects and its own level of evidence.

Delta-9 THC is the compound behind the familiar high; delta-8 and delta-10 are related compounds, and research on them is limited. Synthetic cannabinoids are a separate group made in a lab, so see our post on the risks of synthetic cannabinoids. Below are the main forms of THC, how they interact with the body’s endocannabinoid system, and what research does and does not show about each.

Understanding these differences can help you ask better questions about your medical marijuana use and about the products you buy.

Understanding THC: Basic Chemistry and Effects

THC is the main psychoactive compound found in cannabis and is responsible for the “high” that users experience. THC interacts with the body’s endocannabinoid system, particularly the CB1 receptors in the brain. This interaction produces various effects, such as euphoria, relaxation, and altered sensory perception.

THC is just one of many cannabinoids in cannabis, but it is the most well-known for its psychoactive effects. The concentration of THC can vary widely among cannabis products, affecting the intensity of its effects. Higher levels of THC usually lead to stronger effects, while lower levels may produce milder sensations.

The Different Types of THC

Delta-9 THC

Delta-9 THC is the most commonly known type of THC. When people talk about THC, they usually refer to Delta-9 THC. Cannabinoids are most concentrated in the female flowers of the cannabis plant, NCI notes, and that includes the THCA that turns into delta-9 THC when heated. Delta-9 THC binds strongly to CB1 receptors, resulting in pronounced psychoactive effects.

As the prescription drug dronabinol, delta-9 THC is approved by the FDA for nausea from chemotherapy and appetite loss in AIDS, and NIH’s NCCIH notes modest evidence for chronic pain. In Florida’s medical marijuana program, a qualified physician decides whether it fits a patient’s condition.

Delta-8 THC

Delta-8 THC is a lesser-known form of THC. Though similar to Delta-9 THC in structure, it has a few key differences. Delta-8 THC is often described as milder than Delta-9 THC. Our post on delta-8 THC covers what to know. Some users describe delta-8 as relaxing, but those are personal reports, not trial results.

Delta-8 THC is often marketed for therapeutic or medical uses, but FDA has received adverse event reports including anxiety, hallucinations and vomiting, and it is not FDA-approved for any use. A 1995 study gave it to 8 children with cancer to prevent chemotherapy vomiting, with no control group.

Delta-10 THC

Delta-10 THC is one of the newer cannabinoids to be identified, and research on it is still ongoing. Delta-10 THC has a similar structure to Delta-9 and Delta-8, and sellers describe its effects as more energetic and uplifting. It is said to be less psychoactive than delta-9 THC, but that comparison is unproven, and NIDA notes that research on delta-10 THC is limited.

Claims that it boosts mood, energy or focus come from sellers and users and are unproven.

THCA (Tetrahydrocannabinolic Acid)

THCA is a non-psychoactive cannabinoid found in raw cannabis. THCA becomes THC through a process called decarboxylation, which occurs when cannabis is heated. Unlike the other forms of THC, THCA does not produce any psychoactive effects.

In lab tests on colon cells and tissue, THCA showed anti-inflammatory activity, and in rats and shrews it reduced signs of nausea and vomiting, but no study cited here tested THCA in people. Federal hemp rules describe decarboxylation as the reaction that converts THCA into delta-9 THC, “the intoxicating component of cannabis,” so a THCA product that is smoked, vaped or baked can cause a high.

THCV (Tetrahydrocannabivarin)

THCV is another cannabinoid whose effects in people are not well studied. THCV is similar in structure to THC but has different effects. Sellers describe clear-headed, stimulating effects, but those are claims rather than trial results.

In a 2016 randomized pilot trial of 62 people with type 2 diabetes, THCV lowered fasting blood sugar compared with placebo; claims that it aids weight loss are not established.

THCP (Tetrahydrocannabiphorol)

THCP is one of the recently discovered types of THC, and it is structurally similar to Delta-9 THC but binds more strongly to CB1 receptors. A 2019 lab and mouse study that first identified THCP found it was more active than delta-9 THC in mice.

NIDA notes that research on THCP is limited, so claims of stronger pain relief are unproven.

THC-O Acetate

THC-O Acetate is a synthetic cannabinoid created from THC. Users describe it as stronger than delta-9 THC, but controlled human data are lacking.

THC-O acetate has no approved medical use and little human research, and heating it, as in vaping, may form ketene, a gas that harms the lungs.

Pharmaceutical THC: Synthesized for Medical Use

Pharmaceutical THC products are synthesized for consistent dosing and purity. These products are made to give a consistent, measured amount of THC. Common examples include dronabinol, approved for chemotherapy nausea and vomiting and for appetite loss with weight loss in individuals with AIDS, and nabilone, a related synthetic cannabinoid that the FDA approved for chemotherapy nausea and vomiting.

Pharmaceutical THC gives prescribers a standardized form of THC, without the variability found in naturally occurring THC products. These are standardized prescription drugs, though they still have side effects and risks.

What the Evidence Shows for Different THC Types

Delta-9 THC has the strongest evidence: as dronabinol, it is the only type with FDA-approved uses. Evidence for delta-8 and delta-10 THC rests mostly on user reports.

THCA, THCV and THCP have only early lab, animal or small pilot data, so their benefits are unconfirmed. THC-O acetate has the same gap in evidence, and heating it can form ketene gas.

Considerations and Legal Status

The legal status of THC types varies depending on location. Marijuana with delta-9 THC is allowed under state medical programs such as Florida’s and, when it falls under a state medical marijuana license, is classed in federal Schedule III, still a federally controlled substance. Delta-8, delta-10 and other hemp-derived THC products face a narrower federal hemp definition that starts November 12, 2026, with a later law delaying parts of it, including the 0.4 mg per-container THC limit and the rule on natural cannabinoids made outside the plant, until at least December 11, 2026. It’s important to check local laws and regulations before purchasing or using any THC products.

Different types of THC also come with various effects and potential risks. If you are new to cannabis or have other health conditions, ask your physician first. THC can cause side effects such as a faster heart rate and short-term memory problems.

When you see your physician, bring a list of your current medicines so they can be checked for interactions with THC.

Which Type of THC Has the Most Evidence?

Delta-9 THC has been studied far more than any other type, and none of the studies cited here for the other types is a large trial in people. The less a type of THC has been studied, the less anyone can say about its safety.

If you live with chronic pain or anxiety, knowing the specifics of each type helps you weigh claims against evidence.

At Dr. Green Relief, our Florida medical marijuana doctors can go over these types of THC with you at an evaluation or a renewal visit, alongside your current medications.

Have questions about different THC types and your health? Contact us today to learn whether medical marijuana fits your situation.

Last updated October 18, 2026 by the Dr. Green Relief Editorial Team.

Medical review

Medically reviewed by Achilles Kalnoky, M.D.

Reviewed on October 16, 2026.

He is licensed in Florida as a medical doctor, license ME115088, which you can check on the Florida Department of Health license lookup.

His review covers the medical statements in this post and the sources cited for them.

The Different Types of THC and What Research Shows

Understanding THC: Basic Chemistry and Effects