Having a dry mouth on keto can be VERY uncomfortable. It can happen anytime your body is not producing enough saliva. Often times, it happens as a side effect of the ketogenic diet. However, the problem can also occur during extended fasting. Generally, it is not a cause for major concern and can be fixed at home.
There are a few reasons why you may develop a dry mouth on keto. Lack of hydration, nutrient deficiencies, and the effects of keto-adaptation are just a few of them. There are others of course. Fortunately, experiencing dry mouth from the ketogenic diet can easily be fixed.
If you have a dry mouth on keto, you could be experiencing these symptoms.
- Dry Mouth
- Difficulty Swallowing
- Fruity Breath
- Strange Taste in the Mouth
5 Possible Causes of Dry Mouth on Keto
Let’s break down the possibilities.
Ketosis will change your body as it fat adapts. For example, It causes the kidneys to release salt more freely. You need that salt since it aids with water retention. You’ve also made changes to your eating habits, and this may or MAY NOT be a good thing. It depends on what foods you’ve cut out and what foods you added in. In addition, there are HUNDREDS of medications that are known to cause dry mouth symptoms.
1. Natriuresis of Fasting Dumps Electrolytes
The “Natriuresis of Fasting” is a state that the body goes into during the ketogenic diet. It is also triggered when carbohydrates are restricted below 60g per day. 
When the body enters into this state, the kidneys begin flushing sodium. As the body attempts to conserve sodium, it ALSO flushes potassium. So, we end up losing two VERY important electrolytes that play a big role in fluid regulation. 
Without these electrolytes to manage fluid levels, your body may become dehydrated. This may lead to a dry mouth.
Solution – Replenish Sodium and Potassium:
- Consume green leafy vegetables
- Drink bone broth and bouillon broth
- Consume pink Himalayan salt in a drink
Tip: We need roughly 4700mg of potassium per day. Try consuming your greens in smoothies. Also, cook it down with your food to get it in higher amounts.
2. Lack of Hydration
Lack of hydration could be another cause of dry mouth on keto. Water consumption is ESPECIALLY important on the ketogenic diet. We need more of it than usual, and let me explain why that is the case.
It is common for someone to lose between 3 and 10 pounds of water weight after starting keto. The reason for this is that water molecules follow glycogen in the body. With keto, we are depleting those glycogen stores. [*]
We store between 3 and 4 grams of water per gram of stored glycogen. The bigger our muscles are, the more water there is to lose. 
The rule “eight – 8 oz glasses of water” isn’t nearly enough for most people.
The Mayo Clinic Now Recommends:
- Men – 100 oz of water per day
- Women – 73 oz of water per day
Note: It is assumed that 20 percent of your fluids are coming from foods.
If you are active, you’ll need more water than that.[*]
And, Some health practitioners are recommending up to 140 oz of water or (even more) for the ketogenic diet.
Solution – Hydrate your Body (and Mouth):
- Carry a bottle of water with you wherever you go
- Chew sugar-free gum to stimulate saliva glands (xylitol helps) [*]
- Use a mouth rinse to lubricate the mouth [*]
- Limit use of diuretics such as coffee and caffeine
- Limit the use of carbonated beverages
3. Nutrient Deficiencies
Nutrients such as Omega-3’s, Vitamin D, Vitamin E, Vitamin B6, Vitamin B12, Folate, and Vitamin C are very important for alleviating dry mouth. Many of these happen to show up on my best vitamins for keto list. According to two studies below, these vitamins play a role in maintaining proper salivary health.
There was a 2016 study conducted on oral dryness AND diet in Japanese men. They found dry mouth symptoms in people who had low amounts of Omega-3’s, Vitamin D, Vitamin B6, Folate, and Potassium. It was also no surprise that these people were not eating as many vegetables, fish, and shellfish as the group without dry mouth symptoms. [*]
Another study found that Omega-3 supplements were important for increasing salivary flow. They also focused their patients on consuming enough Vitamin B12, Folate, Vitamin E, and Vitamin C. In addition, they noted that Vitamin D deficiency could be a precursor to salivary issues – particularly leading to Sjogren’s syndrome. [*]
This is a great example of why eating a balanced ketogenic diet filled with quality foods is SUPER important. Fat is amazing, but without the proper nutrients from vegetables to support your body, it can be an uphill battle trying to feel your absolute best.
Solution – Ensure you Get These Vital Nutrients:
- Fatty fish such as Salmon and Halibut
- Grass Fed Beef is a great source of B12
- Green leafy vegetables such as Kale, Spinach, and Broccoli
- Enjoy A few minutes of sunshine every day
4. Exhaled Acetone
If you are still fat adapting, you may notice an odd taste in your mouth. This is acetone; It is one of the three ketones that your body produces while burning fat (The others are BHB and acetoacetate). Acetone isn’t necessarily related to a dry mouth, but it can be related.
Acetone often causes a fruity smelling breath and may also taste fruity. Some have reported that it even tastes metallic.
During fat adaptation, your body releases higher amounts of acetone. It is released through both the urine AND the breath. If you drink more fluids, acetone will prefer to leave through your urine instead.
As the body adapts, it will become more efficient with acetone and excrete less of it. This is because it is using more of it. People who test their ketones with urine strips find that they stop working after a while. This is because the strips measure acetone and acetone levels in our urine will change over time.
To be fair – If you believe that you are exhaling acetone, this is a good thing! That means you are in ketosis.
Solution – Managing Acetone
- Allow time for adaptation to complete
- Drink more water
- Use peppermint oil for temporary relief
- Try tapering your fats back until adaptation completes
This last one is not related to keto but it deserves a spot in this list because it so prevalent. Have you started any new medications in CONJUNCTION with keto recently? Dry mouth is one of the most common side effects across all drugs… PERIOD. In fact, if you google “common drug side effects”, you’ll see dry mouth listed in every result in the top 5 google results. [*]
There are several hundred medications known to cause dry mouth as a side effect. Many of these are popular prescription drugs such as SSRIs, benzodiazepines, and ACE inhibitors. [*] Other common drugs include over-the-counter antihistamines and decongestants. [*]
Medications may not be the direct cause of your dry mouth symptoms on keto, but they can certainly contribute.
Solution – Medication Induced Dry Mouth
- It is possible that the body will adjust to the medication [*]
- Seek alternative medications
- Increase hydration, sugar-free gum, and oral mouthwash
There are several possible causes for a dry mouth on keto. Each of these causes can be fixed.
Remember that water is crucial on the ketogenic diet and that you need more of it than usual.
Due to the “natriuresis of fasting” effect, your sodium and potassium supply is going to be running lower than usual. Replenish these via green leafy vegetables, pink Himalayan salt, and bone broth drinks.
Several vitamins and minerals are CRUCIAL when it comes to dry mouth. They include Omega-3’s, Vitamin D, Vitamin E, Vitamin B6, Vitamin B12, Folate, and Vitamin C.
When it comes to fat adaptation, you may experience the taste and smell of acetone. Allow time for adaptation to complete and the acetone should go away on its own.
Last but not least, remember that there are several HUNDRED medications that are commonly responsible for causing dry mouth symptoms.
Share Your Experience!
Do you have your own experience with dry mouth on keto? Leave it in the comments below! What did YOU do to remedy the problem?
Offline Sources Art and Science of Low Carbohydrate Living. Chapter 2  Art and Science of Low Carbohydrate Living. Chapter 12  Art and Science of Low Carbohydrate Living. Chapter 4