Cannabinoid Hyperemesis Syndrome: How Long to Recover

How long does it take to recover from cannabinoid hyperemesis syndrome? There are two answers: a single vomiting episode usually settles within about 48 hours [1], but full recovery, meaning no more episodes, comes only after cannabis use stops and can take weeks to months. Gastroenterologists now judge recovery over at least 6 months without cannabis, or a span equal to three of the person's typical vomiting cycles [2]. In a systematic review of the published cases, symptoms resolved after stopping cannabis in 96.8% of them [3]. Anyone who is vomiting repeatedly, cannot keep fluids down or shows signs of dehydration should get medical help the same day.

What cannabinoid hyperemesis syndrome is

Cannabinoid hyperemesis syndrome (CHS) is a pattern of repeated, severe vomiting episodes in people who have used cannabis regularly over a long period. It looks like a paradox, because cannabis is known for easing nausea, yet long-term use can have the opposite effect [4]. The condition was first described in 2004 in a series of patients in South Australia, most of whom got better when they stopped using cannabis [5].

The international Rome IV criteria list CHS as one of the nausea and vomiting disorders of the gut [6]. A 2024 clinical practice update from the American Gastroenterological Association sets out what doctors look for [2]:

• Episodes of vomiting that come and go, at least 3 times a year.
• Cannabis use for more than 1 year before the symptoms began, on average more than 4 times a week.
• Relief of the episodes after a sustained stop: at least 6 months, or at least as long as three typical vomiting cycles.

Many people with CHS find that long hot showers or baths ease the nausea for a while. In the systematic review, 92.3% of cases reported this [3]. It is a clue, not a test: about half of people with cyclic vomiting syndrome who do not use cannabis bathe the same way [7]. Only a doctor can rule out the other causes of repeated vomiting, which is why the diagnosis is made after examination and tests, not from a checklist.

The three phases of CHS

Clinicians describe the illness in three phases [1]. The time each one lasts is the core of the recovery question.

Phase	What happens	How long it usually lasts
Prodromal	Early morning nausea, fear of vomiting, stomach discomfort; eating is still normal [1]	Months or years [1]
Hyperemetic	Intense, repeated vomiting, sometimes up to five times an hour, with stomach pain and frequent hot showers [1]	Usually ends within 48 hours [1]
Recovery	Relative wellness, normal eating, weight regained, bathing back to normal [1]	Days, weeks or months [1]

The pattern repeats. Without a stop in cannabis use, a recovery phase is often only the gap before the next episode. In one review, about 70% of patients in a case series lost at least 5 kg during their illness, and in one case series patients made an average of 7.1 emergency visits before diagnosis [1].

How long does it take to recover from cannabinoid hyperemesis syndrome?

Recovery has two clocks, and they run at very different speeds.

The episode. The hyperemetic phase usually stops within about 48 hours [1]. Hospital care during an episode is supportive, for example fluids given into a vein to correct dehydration [3]. That ends the episode; it does not end the condition.

The condition. The episodes stop for good only when cannabis use stops. The systematic review called stopping cannabis the best treatment found so far [3]. How long that takes varies from person to person, and the evidence is thinner than the confident numbers online suggest:

• In the first case series, 7 of the 9 patients described recovered after stopping cannabis. Three restarted after a period without it and became ill again [5].
• In a Mayo Clinic series of 98 patients, only 10 could be followed up. Of the 7 who stopped using cannabis, 6 reported that their symptoms had gone completely [8].
• A 2019 review of the evidence suggested that recovery may take longer than a month. The authors point to the slow clearance of THC, which is stored in fat, and to the time cannabinoid receptors may need to recover. They recommended following people for at least three typical cycles or 6 to 12 months before calling the illness resolved [7].

This is why the AGA update uses at least 6 months without cannabis, or three typical cycles, as the measure of recovery [2]. How fast one person improves varies, and a few good weeks do not yet prove recovery; the long view does.

Does CHS come back?

Yes, if cannabis use starts again. In the 2004 series, three people who had recovered went back to cannabis and their vomiting returned. Two stopped again and stayed well; the third did not stop and stayed ill [5]. In the published cases, the illness followed the cannabis and ended when the cannabis ended [3].

How common is cannabinoid hyperemesis syndrome?

No one knows for certain, because doctors have used different definitions. A survey in the emergency department of the oldest public hospital in the United States asked 155 adults who smoked cannabis on at least 20 days a month about their symptoms, and 32.9% described a pattern consistent with CHS [9]. That study defined CHS mainly by relief from hot showers, so other researchers consider the figure an overestimate [7]. What is clear is that the syndrome is not limited to a rare few among daily users, and that it is often missed: in one series the diagnosis was delayed by up to 9 years [1].

Risks: dehydration, kidney injury and rare deaths

Repeated vomiting drains water and salts from the body, and long hot showers add to the loss. Case reports describe acute kidney failure caused by this dehydration; one 2014 report counted 6 such cases among 55 published CHS cases and called kidney injury a common complication [10]. A 2019 forensic report described three deaths of young adults with a history of CHS; the cause of death in two of them was attributed to the syndrome [11]. Deaths are rare, but they show why an episode of nonstop vomiting is a medical problem, not something to sit out at home.

When to get medical help

General medical guidance on vomiting in adults applies fully to CHS [12]. Contact a doctor or urgent care the same day if a person:

• has been vomiting for longer than 24 hours, or has vomited 3 or more times in one day;
• cannot keep any fluids down for 12 hours or more;
• has not urinated for 8 hours or more;
• has severe stomach pain, or a headache with a stiff neck.

Call emergency services or go to an emergency department if there is blood or dark, coffee-coloured material in the vomit, or if the vomiting may be caused by poisoning [12]. Signs of dehydration include a dry mouth, strong thirst, dark yellow urine or urinating less often, and sunken eyes [12]. Tell the doctor about cannabis use honestly: it is the clue that can shorten the search for the cause.

Stopping long-term daily cannabis use can be hard on its own, and a doctor can help with that as well as with the vomiting. For context on how cannabis affects nausea in other settings, see cannabis, nausea and appetite; for what happens after taking too much at once, which is a different problem, see can you overdose on THC?. The THC vs CBD guide explains the two main cannabinoids.

Frequently asked questions

Does cannabinoid hyperemesis syndrome go away on its own?

A single episode usually settles within about 48 hours [1], but the episodes keep returning while cannabis use continues. In the published cases, symptoms resolved after stopping cannabis in 96.8% of them [3].

How long does a CHS vomiting episode last?

The intense vomiting phase usually ends within 48 hours [1]. If vomiting lasts longer than 24 hours or no fluids stay down for 12 hours, medical guidance is to get help the same day [12].

How long after quitting cannabis does CHS stop?

There is no fixed date. Recovery is judged over at least 6 months without cannabis, or three typical vomiting cycles [2]. Researchers think the slow clearance of THC from fat may explain the delay [7].

Can you die from cannabinoid hyperemesis syndrome?

Rarely. Dehydration can lead to acute kidney failure [10], and a forensic report described deaths in which CHS was the attributed cause [11]. Nonstop vomiting needs medical care.

Will CHS come back if you use cannabis again?

The evidence says it is likely. In the first case series, people who restarted cannabis after recovering became ill again, and those who stopped for good stayed well [5].

Sources

1. Galli JA, Sawaya RA, Friedenberg FK. Cannabinoid hyperemesis syndrome. Current Drug Abuse Reviews. 2011;4(4):241-249. doi:10.2174/1874473711104040241
2. Rubio-Tapia A, McCallum R, Camilleri M. AGA clinical practice update on diagnosis and management of cannabinoid hyperemesis syndrome: commentary. Gastroenterology. 2024;166(5):930-934.e1. doi:10.1053/j.gastro.2024.01.040
3. Sorensen CJ, DeSanto K, Borgelt L, Phillips KT, Monte AA. Cannabinoid hyperemesis syndrome: diagnosis, pathophysiology, and treatment, a systematic review. Journal of Medical Toxicology. 2017;13(1):71-87. doi:10.1007/s13181-016-0595-z
4. Lu ML, Agito MD. Cannabinoid hyperemesis syndrome: marijuana is both antiemetic and proemetic. Cleveland Clinic Journal of Medicine. 2015;82(7):429-434. doi:10.3949/ccjm.82a.14023
5. Allen JH, de Moore GM, Heddle R, Twartz JC. Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis abuse. Gut. 2004;53(11):1566-1570. doi:10.1136/gut.2003.036350
6. Stanghellini V, Chan FK, Hasler WL, Malagelada JR, Suzuki H, Tack J, Talley NJ. Gastroduodenal disorders (Rome IV). Gastroenterology. 2016;150(6):1380-1392. doi:10.1053/j.gastro.2016.02.011
7. Venkatesan T, Levinthal DJ, Li BUK, Tarbell SE, Adams KA, Issenman RM, Sarosiek I, Jaradeh SS, Sharaf RN, Sultan S, Stave CD, Monte AA, Hasler WL. Role of chronic cannabis use: cyclic vomiting syndrome vs cannabinoid hyperemesis syndrome. Neurogastroenterology and Motility. 2019;31(Suppl 2):e13606. doi:10.1111/nmo.13606
8. Simonetto DA, Oxentenko AS, Herman ML, Szostek JH. Cannabinoid hyperemesis: a case series of 98 patients. Mayo Clinic Proceedings. 2012;87(2):114-119. doi:10.1016/j.mayocp.2011.10.005
9. Habboushe J, Rubin A, Liu H, Hoffman RS. The prevalence of cannabinoid hyperemesis syndrome among regular marijuana smokers in an urban public hospital. Basic and Clinical Pharmacology and Toxicology. 2018;122(6):660-662. doi:10.1111/bcpt.12962
10. Habboushe J, Sedor J. Cannabinoid hyperemesis acute renal failure: a common sequela of cannabinoid hyperemesis syndrome. American Journal of Emergency Medicine. 2014;32(6):690.e1-690.e2. doi:10.1016/j.ajem.2013.12.013
11. Nourbakhsh M, Miller A, Gofton J, Jones G, Adeagbo B. Cannabinoid hyperemesis syndrome: reports of fatal cases. Journal of Forensic Sciences. 2019;64(1):270-274. doi:10.1111/1556-4029.13819
12. MedlinePlus Medical Encyclopedia. Nausea and vomiting, adults. US National Library of Medicine; reviewed 22 July 2025. medlineplus.gov

Related: can you overdose on THC?, cannabis, nausea and appetite and THC vs CBD.

Educational information about a medical condition. Not medical advice, not a diagnosis and not a treatment guide. If you are vomiting repeatedly or cannot keep fluids down, contact a doctor or emergency services.