10-OH-HHCP: Effects, Legal Status in Germany and What's Actually Known

10-OH-HHCP stands for 10-hydroxy-hexahydrocannabiphorol. Long name. It's easier in two steps. Start with HHC, a hydrogenated form of THC. Give it a longer side chain, seven carbon atoms instead of five, and you get HHCP. Then add one hydroxyl group to the ring at position 10. That's 10-OH-HHCP. If you want the full chemical name, it's 3-heptyl-6,6,9-trimethyl-6a,7,8,9,10,10a-hexahydrobenzo[c]chromene-1,10-diol, and PubChem files it as compound 172872054.

It's a newcomer. The UK's Advisory Council on the Misuse of Drugs lists every HHC derivative reported to the EU Drugs Agency's early-warning system, and according to that list 10-OH-HHCP was first detected in Europe in July 2024. The EU Drugs Agency's own records show Germany formally notified it on 17 December 2024, the same day as 10-OH-HHC. So it showed up a month after 10-OH-HHC and well after HHCP, which first appeared in late 2022. The same ACMD report notes that 10-hydroxy variants have been found as components of mixtures containing other semi-synthetic cannabinoids. German forensic researchers noticed it too. A 2025 analysis of German seizures closes by pointing to recent reports of a "further generation" of cannabinoids that relied on a hydroxyl group to get around the law at the time, naming 10-OH-HHCP, sold as "10-HCP", as an example.

No. 10-OH-HHCP isn't named in any German law. It doesn't need to be, because it falls under the cannabinoid group definition of the New Psychoactive Substances Act (NpSG), Anlage 1 Nr. 2.3, and since 2 December 2025 that definition has included cannabinoids with a hydroxyl group on the ring. Selling 10-OH-HHCP is a criminal offence. Possessing it is prohibited.

The NpSG isn't a list of names. It defines whole families of substances by their structure, so a new variant is covered the moment it fits the description, whether or not anyone has heard of it yet (which is rather the point). For cannabinoids, the family is group 2.3: compounds built on a specific ring structure, with certain side chains and add-ons allowed, up to a molecular mass of 600 u. 10-OH-HHCP ticks every box.

The hydroxyl clause is the one doing the work. According to the government's explanatory memorandum, the definition was extended to "halogenierte und hydroxylierte Derivate am Ring A", halogenated and hydroxylated derivatives on ring A, "aufgrund von Sicherstellungen". In plain terms: because these substances were being seized.

Plenty of pages get this line wrong.

• Selling, trading, making or importing to sell is a criminal offence. Up to three years in prison or a fine. Selling commercially, as part of a gang, or to a minor when the seller is over 21 carries one to ten years.
• Buying and possessing are prohibited, but the NpSG doesn't make them a crime. What the police can do is seize the substance and destroy it.

HHC works differently. Since 23 May 2026 it has been a narcotic under the Narcotics Act (BtMG), where possession without a permit is a criminal offence on its own. 10-OH-HHCP wasn't part of that change. This is a summary, not legal advice.

That timeline explains why so many pages still call 10-OH-HHCP legal. Most were written between June 2024 and November 2025, when the law covered HHCP but not its hydroxylated version. For about seventeen months, "not covered" was accurate. It stopped being accurate on 2 December 2025, and none of those pages has been updated.

Nothing about 10-OH-HHCP's effects has been measured. No study has tested how it binds to cannabinoid receptors, and there's no animal or human study at all. So if a page gives you an onset time, a duration or a comparison with THC, it's passing on shop copy or user anecdotes.

What does exist is thin. The ACMD says 10-hydroxy variants as a group "are also known to be psychoactive", but that "their psychoactivity is reported to be relatively mild". Read that carefully. "Reported" isn't measured: the ACMD gives no study behind it, and the comment isn't specific to 10-OH-HHCP. The parent compound doesn't get you much further. Receptor tests show HHCP activates the CB1 receptor at lower concentrations than HHC ( Persson et al. 2025), but adding a hydroxyl group can change a cannabinoid's activity in either direction. You can't just carry HHCP's numbers over.

User reports have a second problem. The EU Drugs Agency warns that semi-synthetic cannabinoid products can contain undeclared cannabinoids and vary widely between batches, and the ACMD notes that 10-hydroxy variants have been found in mixtures. Two people describing "10-OH-HHCP" may well have used two different products. Hard to compare notes that way.

There's no clinical or toxicology data on 10-OH-HHCP. No known safe amount, no data on how it interacts with medicines, nothing on long-term use. That doesn't make it safe. It means the risks are unknown.

What can be said comes from related substances and from the market itself.

• Unknown contents. The EU Drugs Agency found that semi-synthetic cannabinoid products can contain undeclared cannabinoids, including delta-9-THC, at concentrations that vary between batches, and says this unpredictability "poses a potential risk of poisoning". A product sold as 10-OH-HHCP may contain something else entirely.
• Psychoactive effects. The ACMD describes 10-hydroxy variants as psychoactive. Germany's Federal Institute for Risk Assessment (BfR) concluded that psychoactive effects are to be expected from HHC-containing products. Driving after using any psychoactive cannabinoid is dangerous.
• Legal risk. Since 2 December 2025, any product containing it can be seized in Germany.

For what's known about side effects across this family, see our 10-OH-HHC effects and side effects guide.

Legally there's no difference at all. Same December 2025 extension of the NpSG, same day.

For the 10-OH-HHC side, see our 10-OH-HHC vs HHC comparison. For HHCP itself, there's what is HHCP.

9H-HHCP isn't a defined chemical compound. It's a shop label. You won't find it in PubChem or the scientific literature, it's never been reported to the EU Drugs Agency under that name, and none of the shops selling it give a formula or a structure. So "99 % 9H-HHCP" on a label doesn't tell you what the 99 % refers to.

Shops can't even agree on what "9H" means for the older 9H-HHC. Some say it stands for a hydroxyl group at position 9. Others use it for a particular form of HHC, and one calls it another name for 10-OH-HHC. For 9H-HHCP, nobody explains it at all. Our 9H-HHC guide goes through the same confusion for the five-carbon version.

So what's actually in a product sold as 9H-HHCP? It could be ordinary HHCP, a hydroxylated HHCP (including 10-OH-HHCP), or a mixture. There's no chemical basis for treating it as the same thing as 10-OH-HHCP, and no basis for treating it as different either. Only a lab report that names the compound against a reference standard can tell you what's in a given product. Those standards exist for HHCP and for 10-OH-HHCP. For anything called 9H-HHCP, there isn't one.

The label doesn't help legally either. Every structure a shop could plausibly mean falls under the same NpSG group 2.3: plain HHCP since 27 June 2024, any ring-hydroxylated version since 2 December 2025. Claims that 9H products are a "legal successor" don't hold up against the wording of the law.

Nobody has studied whether 10-OH-HHCP shows up on standard drug tests. Cannabis screens look for a THC breakdown product. In a small controlled study in Leipzig, with six participants, urine screens came back positive for everyone after HHC ( Höfert et al. 2025). Does the same go for 10-OH-HHCP? Not established, so don't assume you'd test negative. Forensic labs are a different story. Reference standards are commercially available, which means 10-OH-HHCP can be confirmed by chromatography and mass spectrometry.

The previous version of this page told you 10-OH-HHCP was legal in Germany. It listed health benefits, gave dosing tips, and compared it to THC in a table with no source behind any of it. It also said 10-OH-HHCP was made from HHC, which isn't chemically possible. All of that is gone now. A substance that has never been studied and has been banned since December 2025 doesn't need a dosing guide. It needs an honest list of what's known.

That list is short. 10-OH-HHCP is a lab-made variant of HHCP that appeared in 2024, picked up a market reputation in 2025, and got caught by German law on 2 December 2025. Everything said about its effects comes from shops and anecdotes. If a page tells you it's legal, check the date it was written.

Sources

• Advisory Council on the Misuse of Drugs (2025). Semi-synthetic cannabinoids: cannabinoids related to tetrahydrocannabinol and cannabidiol. Table of EU Drugs Agency notifications and section on hydroxy derivatives.
• Hundertmark et al. (2025). Characterising a New Cannabis Trend: Extensive Analysis of Semi-Synthetic Cannabinoid-Containing Seizures From Germany. Drug Testing and Analysis.
• Lindbom K et al. (2024). Human metabolism of the semi-synthetic cannabinoids hexahydrocannabinol, hexahydrocannabiphorol and their acetates using hepatocytes and urine samples. Drug Testing and Analysis 17(3): 372–386.
• Citti C et al. (2019). A novel phytocannabinoid isolated from Cannabis sativa L. with an in vivo cannabimimetic activity higher than Δ9-tetrahydrocannabinol: Δ9-Tetrahydrocannabiphorol. Scientific Reports 9: 20335.
• Persson M et al. (2025). In vitro activation of the CB1 receptor by HHC, HHC-O and HHC-P. Drug Testing and Analysis 17(4): 487–493.
• Höfert et al. (2025). Preliminary pharmacokinetic and psychophysical investigations after controlled oral and inhalative consumption of hexahydrocannabinol (HHC) (Leipzig). Scientific Reports 15: 10086.
• Bundesinstitut für Risikobewertung (2025). Stellungnahme 019/2025 on HHC.
• Cayman Chemical. 10(S)-hydroxy-9(R)-Hexahydrocannabiphorol reference standard.
• PubChem. 10-Hydroxy-HHCP, CID 172872054 and HHCP, CID 175224422.
• EU Drugs Agency (2025). European Drug Report 2025: New psychoactive substances.
• NpSG, Anlage 1 (current consolidated text).
• BGBl. 2025 I Nr. 292 (Sixth ordinance amending the NpSG annex) and Bundesrat printed paper 534/25 (explanatory memorandum).
• BGBl. 2024 I Nr. 210 (Fifth ordinance amending the NpSG annex).
• BGBl. 2026 I Nr. 2 (Act amending the NpSG, renumbering the annex).
• BGBl. 2026 I Nr. 150 (27th ordinance amending the BtMG annexes).