Dry mouth, medically referred to as xerostomia, is the number one phentermine side effect. Weight loss medications like phentermine promote this feeling of dryness in the mouth, lips, and tongue due to their stimulant effect.
Thankfully, most patients report that phentermine dry mouth is only temporary and noticeably improves as treatment progresses.
Does Phentermine Cause Dry Mouth?
Yes, dry mouth is the most common side effect of phentermine weight loss pills (
According to a recent online poll, 4 out of 5 phentermine users experience dry mouth. In fact, dry mouth is a shocking 30% more common than the next most-reported side effect: insomnia.
Phentermine Tongue Side Effects
Phentermine does not have any tongue-specific side effects listed on the box, but they can (and do) sometimes occur secondary to phentermine dry mouth.
Patients with dry mouth are at increased risk for oral yeast infections. Also known as thrush or candidiasis, these infections typically present as a white, clumpy plaque, but may also appear red and irritated. Pain or change in taste is possible but rare (
Phentermine and Dry Mouth
When you take a stimulant like phentermine, epinephrine and norepinephrine levels spike to increase energy. These neurotransmitters also signal the body to divert resources away from non-critical bodily functions like hunger cues and digestion.
So, phentermine causes dry mouth because when the brain sends out a signal to divert resources away from digestion, saliva production in the mouth decreases (
Interestingly, this is the same reason your mouth and lips feels dry when you’re nervous or scared.
Dry Mouth and Bad Breath
Unfortunately, phentermine dry mouth and bad breath often occur together.
The dry oral environment serves as a perfect breeding ground for bacteria, some of which cause bad breath. Due to dryness of the surrounding tissues, some people also experience phentermine dry mouth and sore throat together.
How to Get Rid of Dry Mouth from Phentermine
Thirst is not the only thing that makes your mouth feel dry and uncomfortable while taking phentermine: this cotton-mouth feeling is also a common side effect of stimulants.
So, many patients wonder how to get rid of dry mouth from phentermine. The American Academy of Oral Medicine offers the following remedies (
1. Drink Water
Phentermine produces both extreme thirst and uncomfortable dry mouth, so it’s important to drink plenty of water. Take frequent sips of water or munch on ice throughout the day to keep tissues moisturized.
Hydration also helps suppress hunger, support healthy metabolism and decrease bloating. Carry a bottle of water with you at all times to help you stay hydrated.
2. Pack Sugar-Free Gum & Mints
Chewing gum or sucking on candy and mints encourages the production of additional saliva,which can help alleviate dry mouth.
Plus, since bad breath occurs alongside dry mouth, peppermint or other breath-freshening gum or mints tackle two problems at once by decreasing dryness and improving breath. Just make sure to opt for sugar-free options to minimize extra calories and mitigate cavity risk.
3. Maintain Good Oral Health
Regular checks at the dentist and daily brushing, flossing and rinsing ensure help maintain good oral health.
If you experience prolonged periods of dryness, pay extra attention to your oral health and see your dentist regularly since dental problems like cavities and sores worsen faster if your mouth is dry.
4. Use a Humidifier
A humidifier adds moisture to the air, which can be an effective phentermine dry mouth treatment – especially if you live in a dry climate, use central heating or have chronic respiratory issues. Place a humidifier in your bedroom to help alleviate dry mouth symptoms while you sleep.
5. Eat Foods with High Water Content
Sometimes it’s hard to drink enough water throughout the day. Thankfully, not all hydration needs to come in liquid form.
Eating foods with a high water content can also help. Fresh fruits (e.g. watermelon, strawberries, melon and grapefruit), vegetables (e.g. cucumber, celery, lettuce and peppers) and soup are all great options to boost hydration and combat dry mouth at mealtime (
6. Minimize Caffeinated and Sweet Drinks
Doctors often recommend that patients steer clear of caffeine while taking phentermine due to the medication’s already-strong stimulant effects.
Another reason to skip the morning cup of coffee? Caffeine is a diuretic, meaning that it increases fluid loss. While the occasional coffee, tea or cola can help contribute to your fluid overall intake, it’s unwise to rely on caffeinated drinks as your primary source of hydration.
Likewise, sugary drinks provide extra, unnecessary calories that can slow weight loss and contribute to dental decay. Given that dry mouth speeds dental decay, this is just another reason to choose sugar-free options during your weight loss journey with phentermine.
Instead, stay hydrated with caffeine-free, sugar-free options like water or herbal tea.
7. Invest in Lip Balm
Chapped lips are one of the most annoying symptoms of chronic dry mouth. So, keep an oil-based balm on-hand to soothe dry lips.
8. Use a Saliva Substitute
If at-home phentermine dry mouth remedies are not working, consider using an over-the-counter liquid or gel. These products’ effects are temporary, but may provide some short-term relief.
- Cosentino, G., Conrad, A., & Uwaifo, G. (2013). Phentermine and topiramate for the management of obesity: A review. Drug Design, Development and Therapy, 267. doi:10.2147/dddt.s31443
- Redding, S., & AAOM Web Writing Group. (2015, October 21). Oral Yeast Infections.
- Miranda-Rius, J., Brunet-Llobet, L., Lahor-Soler, E., & Farré, M. (2015). Salivary Secretory Disorders, Inducing Drugs, and Clinical Management. International Journal of Medical Sciences, 12(10), 811-824. doi:10.7150/ijms.12912
- Sankar, V., Rhodus, N., & AAOM Web Writing Group. (2015, October 15). Dry Mouth.
- Breastcancer.org. (2014, March 25). Eating When You’re Dehydrated.