HHC (hexahydrocannabinol) and THCP (tetrahydrocannabiphorol) are two cannabinoids that have surged in popularity on the hemp-derived product market. Both are related to the well-known Delta-9 THC found in marijuana, but they differ significantly in how they’re made, how strong they are, and what they do in your body. HHC is a hydrogenated form of THC with milder effects, while THCP has a longer molecular chain that makes it bind to cannabinoid receptors far more powerfully than regular THC.
How HHC Is Made
HHC was first created in 1944 by chemist Roger Adams, who used a process called hydrogenation to modify the THC molecule. The same basic chemistry is used today: hydrogen atoms are added to THC’s structure, saturating a double bond in the molecule and converting it into hexahydrocannabinol. Think of it like the difference between a vegetable oil and a solid fat. Hydrogenating an oil changes its chemical behavior, and the same principle applies here.
The starting material is typically Delta-8 or Delta-9 THC, which itself is often derived from hemp-sourced CBD through an acid-driven conversion. Metal catalysts like palladium or platinum are used to drive the hydrogenation reaction, yielding HHC at efficiencies of 80 to 92 percent. The process creates two mirror-image versions of the molecule (called diastereomers) in varying ratios depending on which catalyst is used. One version binds more actively to cannabinoid receptors than the other, which means the ratio in a final product can influence its strength in unpredictable ways.
How THCP Is Made
THCP was identified in 2019 by Italian researchers analyzing a medicinal cannabis strain. It occurs naturally in the cannabis plant, but at vanishingly small concentrations, typically between 0.0023 and 0.0136 percent by weight. That’s far too little to extract economically, so commercially available THCP is produced synthetically or semi-synthetically in a lab.
What makes THCP structurally unique is its side chain. Regular Delta-9 THC has a five-carbon chain hanging off one side of the molecule. THCP has a seven-carbon chain. That difference of just two carbon atoms dramatically changes how the molecule interacts with your body’s cannabinoid receptors.
Potency: How They Compare to THC
HHC is generally considered less potent than Delta-9 THC. Users consistently describe its effects as milder, placing it in a similar category to Delta-8 THC. If regular THC is a full-strength experience, HHC is a step or two below.
THCP is the opposite story. In lab studies, THCP’s binding affinity for the CB1 receptor (the receptor responsible for THC’s psychoactive effects) is roughly 33 times stronger than Delta-9 THC’s. The binding constant for THCP at CB1 was measured at 1.2 nanomolar, compared to a range of 5 to 80 nanomolar for THC. Stronger binding doesn’t translate to exactly 33 times the high, because the body’s response plateaus at a certain point, but it does mean THCP is significantly more intense at lower doses. This makes dosing errors with THCP products a real concern, since a small miscalculation can produce an overwhelming experience.
Effects and Side Effects
Because HHC activates the same receptors as THC, its effects follow a familiar pattern: mild euphoria, relaxation, altered time perception, and increased appetite. The side effects mirror THC as well and can include anxiety, dry mouth, dizziness, fast heart rate, impaired coordination, and memory issues. At higher doses, confusion and panic are possible.
THCP’s effects are similar in character but more intense. The stronger receptor binding means the window between a comfortable dose and an uncomfortable one is narrower. Reports of anxiety, paranoia, and sedation are more common when users misjudge the amount. Because THCP is so new to the consumer market (products began appearing around 2023), there is essentially no long-term safety data on it.
Both cannabinoids carry the broader risks associated with THC use. These include potential for dependence, impaired brain development in people under 26, cannabinoid hyperemesis syndrome (a condition involving repeated episodes of severe nausea and vomiting), and risks during pregnancy. Neither has been studied for therapeutic use, and no clinical data supports health claims sometimes made by product manufacturers.
Manufacturing and Purity Concerns
One of the most practical risks with both HHC and THCP products is what else might be in them. The hydrogenation process used to make HHC relies on heavy metal catalysts, specifically platinum and palladium, that are toxic to humans. If manufacturers don’t properly purify their final product, traces of these metals can remain. As Cleveland Clinic physician David Streem has noted, HHC production involves hazardous chemicals that can linger in the finished product.
THCP products face similar quality concerns. Because these cannabinoids are not regulated like pharmaceuticals or even like state-legal marijuana, manufacturers are not required to test for potency, purity, or contaminants. A product labeled as containing a specific amount of THCP may contain more, less, or none at all, potentially mixed with other cannabinoids or chemical byproducts. Third-party certificates of analysis from independent labs are the closest thing to a quality check available, but not all companies provide them, and not all labs are equally reliable.
Drug Testing
If you’re subject to drug testing, both HHC and THCP are likely to cause problems. Standard urine drug screens use antibodies designed to detect THC’s main metabolite, but these antibodies cross-react with structurally similar compounds. Research published in the Journal of Analytical Toxicology found that HHC’s carboxylic acid metabolites triggered positive results across all six commercially available urine screening kits tested, though sensitivity varied by kit and cutoff concentration.
THCP’s situation is less directly studied, but its close structural resemblance to THC makes a positive result plausible. Standard immunoassays are not designed to specifically identify synthetic or semi-synthetic cannabinoids, so a confirmatory test at a reference laboratory would be needed to distinguish THCP from THC. In practical terms, if your employer or probation officer uses a standard panel, you should assume that using either compound could trigger a positive result for cannabis.
Legal Status
The legal landscape for both HHC and THCP is complicated and shifting. The 2018 Farm Bill legalized hemp and hemp-derived products at the federal level, defining legal hemp as cannabis containing no more than 0.3 percent Delta-9 THC by dry weight. Because HHC and THCP are technically distinct from Delta-9 THC, some manufacturers and retailers argue their products fall within this legal definition.
That argument is increasingly contested. The DEA has signaled that synthetically derived cannabinoids may not qualify for the Farm Bill’s hemp exemption, and several states have moved independently to restrict or ban HHC, THCP, and similar compounds. The legal status in your specific state can change quickly, and what’s sold openly in one state may be a controlled substance in the neighboring one. Checking your state’s current regulations before purchasing is the only way to know where you stand.