HHC and Your Mental Health

Hexahydrocannabinol (HHC) is a new semi synthetic cannabinoid product. This information document is for the public who want to know about some of the potential harmful effects of using this product.

We answer 13 frequently asked questions about this drug under three headings:

Background Information
HHC and Its Use in Ireland
Key Messages & Actions

Download HHC and Your Mental Health

Background Information

1. What is HHC?

Hexahydrocannabinol (HHC) is a new semi synthetic cannabinoid product. HHC is chemically like THC. It is designed to imitate the effects of THC, the main psychoactive substance found in cannabis that produces a ‘high’.

HHC has been available on the Irish market since 2022. It is currently available to buy in different forms in high-street shops and online. It is not considered safe to consume by health professionals.

2. What are Cannabinoids?

Naturally occurring cannabinoids

Cannabinoids are the naturally occurring compounds found in the human body as well as inside the cannabis plant. Both have effects on the body and mind.

Cannabinoids affect our body mainly by interacting with a system called the endocannabinoid system. The endocannabinoid system controls our memory, mood, sleep, appetite and fertility.

There are over a hundred different cannabinoids in the cannabis plant, but the two that are most well-known are THC and CBD.

THC is the short name for delta-9-tetrahydrocannabinol, and CBD is short for cannabidiol.

THC and CBD act quite differently in our bodies and with the endocannabinoid system. THC is the psychoactive substance in the cannabis plant that gives you a ‘high’. It can make you feel happy or giddy but also suspicious and paranoid. CBD is obtained from hemp, a form of the Cannabis sativa plant.

Synthetic (man- made) Cannabinoids

Synthetic (man-made) cannabinoids are laboratory made chemicals and are either semi-synthetic or synthetic. Many man-made cannabinoids exist. They are mostly designed to act on the endocannabinoid system and imitate the actions of THC.

These synthetic and semi-synthetic substances carry the risk of negative and dangerous effects on our minds and/or bodies but with a higher risk of negative and dangerous effects on our bodies.

3. How is HHC produced?

HHC is a man-made chemical produced and developed in a lab and from CBD (cannabidiol- a chemical found in cannabis) using a process called hydrogenation.

HHC is chemically like the naturally occurring THC (tetrahydrocannabinol) but is a semisynthetic CBD. Many man-made cannabinoids like HHC are designed to imitate the actions of THC. These synthetic substances carry the risk of negative and dangerous effects on our minds and bodies.

4. When did HHC first emerge?

HHC was first described in the scientific literature in 1940, but it appears to have first been sold in the United States in September 2021.

HHC was initially identified in Europe in May 2022. According to a report from the European Monitoring Centre for Drugs and Addiction (EMCDDA) in early 2024, HHC has now been identified in over 20 European countries. The number of stores selling these products are increasing rapidly.

The EMCDDA has been tracking the substance via the EU Early Warning System (EWS) since October 2022. By December, HHC had been found and identified in 70% of EU member states.

HHC and Its Use in Ireland

5. What are the effects of HHC use?

According to laboratory studies on several animal species, HHC appears to have broadly similar effects to cannabis and THC products.

The pharmacological and behavioural effects of HHC in humans have not been studied, though recent anecdotal reports show that its effects are like that of cannabis.

The effects vary from person to person. Some people will feel elevated mood, happy or euphoric. Some might feel relaxed and have an altered perception.

Anecdotal reports to the Health Service Executive (HSE) also confirm some people have experienced the below effects following the use of HHC:

A stronger and ‘different’ type of intoxication compared with cannabis
General feelings of being unwell
Confusion
Depression
Withdrawal symptoms following frequent use
Collapse
Paranoia and delusions

6. In what form is HHC sold?

HHC can be sold as e-cigarettes, vape pens, herbal mixtures, oils, edibles (jellies and cake) and as tinctures. Some cases have seen HHC sprayed on plant materials which could be confused with cannabis.

7. How is HHC consumed?

It is inhaled in a similar way to cannabis, taken orally as an oil or eaten in edible products. Based on the products available for sale, the most common form of consumption seems to be vaping products.

8. Why are people attending mental health services for addiction because of HHC?

As of July 2024, it is estimated that HHC has been taken by 20% of young people who seek the help of addiction services in Ireland in the preceding year. This is typically in combination with cannabis itself. HHC is the main presenting drug in about 5% of cases. It was not present at all in Ireland before 2022.

9. Are there long-term consequences of taking HHC?

This is not yet known. It generally takes decades for the medical community to figure out long-term consequences of new substances. In the absence of certainty, it seems reasonable to predict that the long-term effects are likely to be similar to those of cannabis. Regular use could impact on both physical and mental health. Learn more about how cannabis is associated with mental illness here.

10. Is there a risk of psychosis?

Psychosis is a condition where people lose touch with reality with symptoms often involving delusions or hallucinations. Psychosis can be a short or long-term condition. Irish cases of HHC use include reports of extreme distress, delusions, auditory hallucinations, paranoia, detachment from reality and self-harm.

Emerging information from Irish hospitals has highlighted two case studies of regular cannabis smokers who experienced psychotic episodes as a possible result of vaping HHC. There are anecdotal reports of many other cases of HHC-induced psychosis from psychiatrists in Ireland.

11. If treatment is required for HHC use, what are the options?

Treatment options are the same as for harms related to cannabis.

Key Messages & Actions

12. What do the public need to know?

The public need to be aware of the potential serious harms to mental health of HHC, whether taken in vapes or edibles.

A substance sold in a shop, in attractive packaging and claiming to be “for human consumption” does not ensure that it is regulated, safe or tested in any meaningful way. Buyers need to be aware of what they are purchasing and of the impacts it may have on their physical and mental health.

Unfortunately, with HHC, the burden of proof lies on society and health professionals to confirm the presence of harm, before action is taken.

13. What needs to be and can be done urgently?

By Law

The Irish government needs to urgently enforce the laws we currently have in place:
1. Under the Psychoactive Substances Act (2010) it is a criminal offence to sell psychoactive drugs. As HHC is a psychoactive product, those who distribute or /and sell it should face criminal sanctions.
2. Under the Misuse of Drugs Act (1977) it is a criminal offence to sell and possess prohibited (illegal) substances. HHC could also be added to the list of prohibited (illegal) substances to ban the sale and possession of it.

In Retail/Wholesale Business

Products containing HHC or similar synthetic products that can be harmful should be banned. Those who produce, distribute or sell HHC should be held responsible and prosecuted under either or both current laws (above).

The Public

The public need to informed and aware of the potential serious harms of HHC to their health. Consuming HHC can have extremely harmful effects both physically and mentally. Incidences of severe psychosis have been noticed in some addictions services as a direct result of taking HHC.