What illicit drugs cause dry mouth?

September 26, 2025 •

4 min read

According to the American Dental Association, reduced saliva flow, or xerostomia, is a common oral health concern. A number of substances, including many illicit drugs, can significantly decrease saliva production, and understanding what illicit drugs cause dry mouth is crucial for recognizing the serious risks involved.

Quick Summary

Methamphetamine, cannabis, ecstasy (MDMA), cocaine, and opioids are among the illicit substances known to cause dry mouth (xerostomia), which can severely impact oral health through various mechanisms, including nervous system disruption and dehydration.

Key Points

Stimulant Risk: Methamphetamine, cocaine, and ecstasy significantly reduce saliva production through nervous system effects, leading to severe dry mouth and increased dental damage.
Opioid Impact: Heroin and other opioids depress the central nervous system, which slows saliva secretion and can lead to severe tooth decay due to both dry mouth and sugar cravings.
Cannabis Effect: Cannabis is a common cause of 'cottonmouth,' a form of dry mouth resulting from THC interference that raises the risk of periodontal disease and cavities.
Chronic Complications: Persistent dry mouth from illicit drug use increases the risk of tooth decay, gum disease, and oral infections like thrush.
Managing Symptoms: Increasing hydration, chewing sugar-free gum, and using saliva substitutes are effective methods for managing dry mouth symptoms and protecting oral health.

The Importance of Saliva and the Dangers of Xerostomia

Saliva plays a critical role in maintaining oral health. A healthy person produces up to three pints daily, and this fluid does far more than just moisten food. Saliva helps neutralize acids produced by bacteria, remineralize tooth enamel, and wash away food particles, which prevents tooth decay and gum disease. It also contains antibacterial enzymes that help fight oral infections.

Chronic dry mouth, or xerostomia, occurs when the salivary glands don't produce enough saliva, leading to serious oral health complications over time, including rapid tooth decay, gum disease, and oral infections like thrush. Furthermore, xerostomia can make chewing, swallowing, and speaking difficult, significantly affecting a person's quality of life. For individuals using illicit substances, drug-induced xerostomia is a significant—and often overlooked—health risk.

A Closer Look at Illicit Drugs and Their Effects on Saliva Production

Numerous illicit drugs are known to cause or exacerbate dry mouth. The effects differ depending on the drug's mechanism of action, but the result is consistently detrimental to oral health.

Stimulants: Methamphetamine, Cocaine, and Ecstasy (MDMA)

Stimulants are a major cause of severe dry mouth, often through their impact on the nervous system and tendency to cause dehydration.

Methamphetamine (Meth): This drug is notoriously linked to a condition known as "meth mouth," characterized by extensive tooth decay. Meth causes severe vasoconstriction, which restricts blood flow to the salivary glands, directly reducing saliva output. Its stimulant properties also contribute to teeth grinding (bruxism) and intense sugar cravings, further compounding oral damage.
Cocaine: Snorting or rubbing cocaine on the gums can cause localized tissue damage and gum ulceration. Like meth, it's a stimulant that causes a significant reduction in saliva, creating an environment where decay-causing bacteria can thrive.
Ecstasy (MDMA): A common side effect of ecstasy use is severe dry mouth, along with involuntary teeth grinding and jaw clenching. These effects can persist for up to 48 hours and contribute to enamel erosion.

Depressants: Heroin and Opioids

While stimulants actively interfere with salivary nerve function, depressants like opioids slow down the body's involuntary processes, including saliva production.

Heroin and Other Opioids: These drugs can dramatically reduce saliva production. People using opioids may also develop intense cravings for sugary foods, which, when combined with poor oral hygiene and a lack of saliva, dramatically increases the risk of tooth decay and crumbling teeth.

Cannabis (Marijuana)

Cannabis is well-known for causing the sensation of "cottonmouth," a dry, sticky feeling in the mouth.

THC's Effect: Research has shown that the psychoactive compound THC (delta-9-tetrahydrocannabinol) in marijuana can cause short-term hyposalivation. One study noted that a significant majority of users experienced dry mouth almost immediately after consumption. The smoke itself, along with reduced saliva, also increases the risk of periodontal disease.

The Mechanisms Behind Drug-Induced Xerostomia

The specific ways different drugs cause dry mouth vary, but they all ultimately disrupt the complex process of saliva secretion, which is controlled by the autonomic nervous system.

Nervous System Interference: Many drugs, particularly those with anticholinergic or sympathomimetic actions, interfere with the nerve signals that stimulate the salivary glands. Stimulants, for example, can trigger excessive sympathetic nervous system activity, altering the type and amount of saliva produced. Opioids, by depressing the central nervous system, can suppress the signals for saliva production.
Vasoconstriction and Dehydration: As seen with meth, some drugs cause vasoconstriction, or narrowing of the blood vessels, which reduces blood flow to the salivary glands and decreases saliva output. Dehydration caused by stimulants also directly limits the body's ability to produce sufficient saliva.
Behavioral Factors: Chronic drug use can lead to poor diet, neglect of oral hygiene, and frequent consumption of sugary drinks to combat the dry mouth feeling, which all worsen the dental damage.

Comparison of Illicit Drugs and Their Oral Effects


Drug Class	Primary Dry Mouth Mechanism	Other Oral Health Risks	Severity of Xerostomia
Stimulants	Nervous system interference, vasoconstriction, dehydration	Bruxism (teeth grinding), enamel erosion, tooth decay, gum lesions, sugar cravings	Often severe
Opioids	Central nervous system depression, affecting autonomic functions	Sugar cravings, tooth decay, potential for tooth loss, poor oral hygiene	Can be severe and chronic
Cannabis	Interference with salivary glands via THC	Increased risk of periodontal disease, tooth staining, oral candidiasis	Common, often pronounced

Managing and Mitigating Drug-Induced Dry Mouth

For individuals struggling with substance use, addressing dry mouth is a critical part of a broader health strategy. Prevention and management are key to minimizing serious oral health consequences.

Stay Hydrated: Sip water or sugar-free drinks regularly throughout the day. This is the most direct way to combat dehydration and keep the mouth moist.
Stimulate Saliva Flow: Chew sugar-free gum or suck on sugar-free candies. Products containing xylitol can also help enhance saliva production and prevent tooth decay.
Use Saliva Substitutes: Over-the-counter sprays, gels, and lozenges designed for dry mouth can provide temporary relief, especially at night.
Avoid Irritants: Steer clear of caffeine, alcohol, and tobacco, as these can worsen dry mouth symptoms. Also, avoid alcohol-based mouthwashes.
Practice Excellent Oral Hygiene: Brush teeth gently twice daily with a fluoride toothpaste and floss once a day to help combat the increased risk of cavities and gum disease.
Use a Humidifier: Running a humidifier at night can add moisture to the air and help alleviate nocturnal dry mouth symptoms.
Seek Professional Help: A dentist can monitor oral health, and a doctor can address the root cause, which may involve seeking help for substance use disorder. A good resource for managing dry mouth is the National Institutes of Health information on xerostomia.

Conclusion

Drug-induced dry mouth is a serious condition with severe and lasting consequences for oral health. The array of illicit drugs causing this issue—from stimulants like methamphetamine and cocaine to depressants like opioids and even cannabis—affects saliva production in various harmful ways. By understanding the causes and risks of dry mouth, individuals can take proactive steps toward managing their oral health and seeking the necessary support to address substance use and its related health problems.

Frequently Asked Questions

Drug-induced dry mouth, or xerostomia, is a condition where the salivary glands don't produce enough saliva due to the effects of medication or illicit substances. This lack of saliva can lead to significant oral health problems.

Illicit drugs cause dry mouth by interfering with the autonomic nervous system, which controls saliva production. Stimulants can cause dehydration and vasoconstriction, while depressants can slow down overall bodily functions, both of which reduce saliva flow.

Methamphetamine causes severe dry mouth by constricting blood vessels to the salivary glands, drastically reducing saliva production. This, combined with drug-related bruxism and poor hygiene, accelerates tooth decay and damage, leading to 'meth mouth'.

Cannabis (marijuana) typically causes a temporary dry mouth effect known as 'cottonmouth'. While this effect usually subsides, long-term use can contribute to chronic oral health problems like periodontal disease due to repeated exposure to dry mouth conditions.

Yes, chronic dry mouth can lead to serious, long-term complications including rampant tooth decay, cavities, gum disease, oral thrush, and difficulty speaking or swallowing. The absence of saliva's protective properties makes the mouth highly vulnerable.

To get relief, you can increase your water intake, chew sugar-free gum or candy to stimulate saliva, use over-the-counter saliva substitutes, and run a humidifier at night. Avoiding caffeine, alcohol, and tobacco also helps.

You should see a healthcare professional if dry mouth symptoms are persistent, severe, or are causing discomfort despite home care efforts. It is especially important to seek help if you notice signs of decay, gum disease, or oral infections.