Supplements for Dry Mouth: What Works, What Doesn't, and What to Check First

The short version

• Malic acid 1% mouth spray: improved dry-mouth scores and saliva flow. B Grade B · 5 trials, 244 people, 2 weeks (Liu 2023).
• Saliva substitutes and sugar-free gum: they help some people for a short time, but the trials are mostly low quality. C Grade C (Cochrane, Furness 2011).
• Betaine toothpaste and mouth products: small trials found symptom relief. C Grade C (Söderling 1998; Rantanen 2003). The studies tested products used in the mouth. Betaine capsules have no dry-mouth trial.
• Omega-3 capsules: no clear difference from a placebo oil in people with Sjögren's. C Grade C (Singh 2010; Nave 2024).
• Carnosine and hibiscus tablet: one 6-day trial found more saliva. D Grade D (Levrini 2020).
• Your medicines: drugs for bladder control, antidepressants and other psychiatric medicines are strongly linked to dry mouth in people 60 and over (Tan 2018).

About 22% of people report a dry mouth, and it's more common with age (Agostini 2018). The medical name is xerostomia, meaning the feeling of a dry mouth. It matters beyond comfort: saliva protects teeth, so a dry mouth raises the risk of cavities, tooth sensitivity and thrush (a yeast infection in the mouth) (American Dental Association, Plemons 2014).

Check your medicines first

In a review of 52 studies of people aged 60 and over, three groups of drugs stood out (Tan 2018):

The more medicines a person took, the more likely dry mouth was. The American Dental Association's guidance starts dry-mouth care with a detailed health history to find the cause, and it names medicines as a common one (Plemons 2014). Don't stop a prescribed medicine on your own. Ask the prescriber or a pharmacist whether a different drug, dose or timing could help.

What has the best evidence: malic acid mouth spray

B Grade B. A 2023 meta-analysis pooled five randomised trials with 244 people who used a 1% malic acid spray or a placebo spray for two weeks. The malic acid groups had better scores on three dry-mouth questionnaires and made more saliva, both at rest and when stimulated (Liu 2023). Malic acid is a mild fruit acid that prompts the glands to release saliva.

In one double-blind trial of 41 people with an average age of 79, 21 used the malic acid spray when needed for two weeks and 20 used a placebo spray. In the malic acid group, the score on the Xerostomia Inventory (a standard dry-mouth questionnaire) fell from 36.4 to 29.1 points, a change the authors called clinically meaningful, and saliva flow rose (Gómez-Moreno 2014). That spray also contained xylitol and fluoride.

Limits: the trials were small and lasted only two weeks, and the meta-analysis authors called for larger ones. These sprays are mouth products, not supplements you swallow.

Saliva substitutes and sugar-free gum

C Grade C. A Cochrane review of 36 randomised trials (1,597 people) covered sprays, gels, lozenges, rinses, gums and toothpastes. Only one trial was at low risk of bias, and the reviewers found "no strong evidence … that any topical therapy is effective" for the symptom of dry mouth (Furness 2011). Within that:

• One saliva substitute (an oxygenated glycerol triester spray) beat a plain electrolyte spray by about 2 points on a 10-point dryness scale.
• Sugar-free chewing gum raised saliva output in people whose glands still worked. It was no better or worse than saliva substitutes.

A 2025 review of 48 systematic reviews reached the same conclusion: substitutes and stimulants mostly act as short-term moisturisers, and more than 80% of the reviews were of "critically low" quality (Conte 2025).

Betaine: a mouth-product ingredient, not a capsule

C Grade C. Betaine (trimethylglycine) is added to some dry-mouth toothpastes because it makes them less irritating. Four small trials tested betaine in mouth products:

• A 13-person crossover trial of a 4% betaine toothpaste found relief of several dry-mouth symptoms over two weeks (Söderling 1998).
• A trial in 27 people with dry mouth (plus 18 healthy controls) found that the betaine toothpaste relieved symptoms in 44% of patients, against 7% with the comparison paste (Rantanen 2003).
• In 90 people who finished a 4-week trial, a betaine mouthwash, a night guard, or both all eased symptoms. There was no placebo group (López-Jornet 2012).
• A one-week open-label crossover in 40 adults found that a set of products with olive oil, betaine and xylitol raised resting saliva flow and eased symptoms (Ship 2007).

Our database page rates this betaine evidence B. We rate it C here because the trials were small, short and partly unblinded, and because none tested betaine taken by mouth. Betaine capsules (sold for digestion or for homocysteine) have no dry-mouth trial, so we don't suggest them for it. See the betaine page for what those capsules were studied for.

Supplements you swallow

Omega-3 fatty acids

C Grade C, no clear benefit. In a randomised, double-masked pilot trial of 61 people with Sjögren's syndrome, an omega-3 supplement was no better than wheat germ oil at raising saliva; the differences were not statistically significant (Singh 2010). A 2024 review of six omega-3 and omega-6 trials in Sjögren's found that most showed no significant effect on symptoms (Nave 2024). Our dry-mouth protocol lists omega-3 and vitamin E as its core, but no trial we found supports either for dry mouth. See omega-3 and fish oil for the uses where they do have evidence.

Carnosine with hibiscus (Aqualief)

D Grade D. In one randomised, placebo-controlled trial, 60 people with mild to moderate dry mouth took a carnosine and Hibiscus sabdariffa tablet three times a day for six days. Resting saliva rose 56%, against 19% with placebo (Levrini 2020). That's one short trial of one branded product, so it needs repeating before anyone can rely on it. (Carnosine on Winnowleaf.)

What we'd skip

• Betaine HCl or betaine (TMG) capsules for dry mouth: the evidence is for toothpaste and mouthwash, not capsules.
• Omega-3 or vitamin E "for dry mouth": no trial shows a benefit.
• Multi-ingredient "saliva support" pills with no published trial of that product: there's nothing to grade.

Safety and interactions

• Medicines: if a drug is the cause, the fix is a medicine change agreed with your prescriber, not a supplement on top.
• Malic acid spray: it's a mild acid. The tested sprays also contained fluoride and xylitol (Gómez-Moreno 2014). If you have enamel erosion or sensitive teeth, ask your dentist which product suits you.
• Teeth: a dry mouth raises cavity risk. Topical fluoride and regular check-ups are part of standard care (Plemons 2014).
• Prescription saliva stimulants exist and are for a clinician to consider. A 2025 umbrella review found low-quality evidence that pilocarpine raises saliva after head and neck radiotherapy (Conte 2025).
• For the safety of omega-3, vitamin E or carnosine taken for other reasons, see each supplement's page.

When to see a doctor or dentist

See a clinician if:

• dry mouth lasts more than a few weeks, or began after a new medicine;
• your eyes are dry too. Sjögren's syndrome, an autoimmune condition, causes both (Nave 2024);
• you have mouth sores or burning, trouble swallowing or speaking, new cavities, or white patches;
• you've had radiotherapy or chemotherapy. Cancer treatment is a known cause (Furness 2011), and your care team should manage it.

Other known causes include hormone disorders and infections (Furness 2011). If you're pregnant, breastfeeding or under 18, ask a clinician before trying any product.

FAQ

What is the best supplement for dry mouth? No swallowed supplement has good evidence for dry mouth. The best-tested product is a 1% malic acid mouth spray (grade B, five small two-week trials). Saliva substitutes and sugar-free gum give short-term relief for some people (grade C).

Does omega-3 help dry mouth? Not on current evidence. In a 61-person trial in Sjögren's syndrome, an omega-3 supplement did no better than wheat germ oil at raising saliva, and most omega-3 trials in Sjögren's found no significant effect (grade C).

Is betaine good for dry mouth? Betaine toothpastes and mouth products eased symptoms in small trials (grade C). Betaine capsules have not been tested for dry mouth.

Is xylitol good for dry mouth? In the trials we checked, xylitol was always one ingredient among several (for example, in the malic acid sprays and the olive oil and betaine products), so its own effect on dry mouth isn't known.

Can medication cause dry mouth? Yes. In people over 60, drugs for overactive bladder, antidepressants and sedative or antipsychotic medicines were strongly linked to dry mouth, and the risk rose with the number of medicines. Ask your prescriber before changing anything.

Related pages on Winnowleaf

• All graded dry-mouth findings
• Dry mouth (xerostomia) supplement stack, with doses
• Dental and oral health stack
• Betaine · Omega-3 fatty acids · Fish oil · Vitamin E · Carnosine
• How we grade evidence (A–D)

Sources

1. Liu G, et al. Efficacy of a 1% malic acid spray for xerostomia treatment: a systematic review and meta-analysis. Oral Dis. 2023. PubMed 34954846 · doi:10.1111/odi.14116
2. Gómez-Moreno G, et al. Evaluation of the efficacy of a topical sialogogue spray containing malic acid 1% in elderly people with xerostomia: a double-blind, randomized clinical trial. Gerodontology. 2014. PubMed 23294350 · doi:10.1111/ger.12034
3. Furness S, et al. Interventions for the management of dry mouth: topical therapies. Cochrane Database Syst Rev. 2011. PubMed 22161442 · doi:10.1002/14651858.CD008934.pub2
4. Conte DB, et al. Systematic reviews on the management of xerostomia and hyposalivation: an umbrella review. Gerodontology. 2025. PubMed 39838537 · doi:10.1111/ger.12809
5. Tan ECK, et al. Medications that cause dry mouth as an adverse effect in older people: a systematic review and metaanalysis. J Am Geriatr Soc. 2018. PubMed 29071719 · doi:10.1111/jgs.15151
6. Agostini BA, et al. How common is dry mouth? Systematic review and meta-regression analysis of prevalence estimates. Braz Dent J. 2018. PubMed 30517485 · doi:10.1590/0103-6440201802302
7. Plemons JM, et al. Managing xerostomia and salivary gland hypofunction: executive summary of a report from the American Dental Association Council on Scientific Affairs. J Am Dent Assoc. 2014. PubMed 25082939 · doi:10.14219/jada.2014.44
8. Söderling E, et al. Betaine-containing toothpaste relieves subjective symptoms of dry mouth. Acta Odontol Scand. 1998. PubMed 9669455 · doi:10.1080/00016359850136003
9. Rantanen I, et al. Effects of a betaine-containing toothpaste on subjective symptoms of dry mouth: a randomized clinical trial. J Contemp Dent Pract. 2003. PubMed 12761586
10. López-Jornet P, et al. Evaluation of the clinical efficacy of a betaine-containing mouthwash and an intraoral device for the treatment of dry mouth. J Oral Pathol Med. 2012. PubMed 21950587 · doi:10.1111/j.1600-0714.2011.01088.x
11. Ship JA, et al. Safety and effectiveness of topical dry mouth products containing olive oil, betaine, and xylitol in reducing xerostomia for polypharmacy-induced dry mouth. J Oral Rehabil. 2007. PubMed 17824884 · doi:10.1111/j.1365-2842.2006.01718.x
12. Singh M, et al. Effect of omega-3 and vitamin E supplementation on dry mouth in patients with Sjögren's syndrome. Spec Care Dentist. 2010. PubMed 21044101 · doi:10.1111/j.1754-4505.2010.00158.x
13. Nave CBD, et al. The effect of polyunsaturated fatty acid (PUFA) supplementation on clinical manifestations and inflammatory parameters in individuals with Sjögren's syndrome: a literature review of randomized controlled clinical trials. Nutrients. 2024. PubMed 39519619 · doi:10.3390/nu16213786
14. Levrini L, et al. The efficacy of a dietary supplement with carnosine and Hibiscus sabdariffa L. (Aqualief) in patients with xerostomia: a randomized, placebo-controlled, double-blind trial. Clin Ter. 2020. PubMed 32614361 · doi:10.7417/CT.2020.2231