I have been having dry mouth while sleeping for about the past three years and it has been slowly worsening over the three year period. Lately it was almost as though my mouth was glued shut when I would wake up during the night and it would hurt to open it.
I've tried several natural treatments such as coconut oil, vitamin e, vitamin d, increased water intake throughout the day, fish oil at high dosage, krill oil, black currant oil, diatomaceous earth, different toothpaste, vitamin c, potassium citrate, different types of magnesium including topical magnesium chloride, b vitamins, mineral supplements, hydrochloric acid and digestive enzymes to name several.
I had recently purchased a 16 ounce bottle of food grade vegetable glycerin for another purpose, but decided to try using it while brushing my teeth. I think some toothpastes have glycerin in it already, but in relatively small amounts. Biotene, a popular mouth rinse used for dry mouth, has glycerin listed as the second ingredient after purified water.
I brush my teeth as usual and before I rinse my mouth, I put as much glycerin as will stay on my toothbrush and brush a little more being sure to brush my gums and tongue also. I try to be as generous as possible with the glycerin and will usually reload my brush a second time and then rinse my mouth when done brushing.
Anyway, it adds about a minute to my total brushing time and the bottom line is that my night time dry mouth is hugely improved and seems to be continuing to get better, currently being close to what I remember as normal. I noticed a definite benefit after a week although there may have been improvement before then, but I may not have associated the benefit to the glycerin right away as I wasn't paying that close attention. The glycerin seems to be effective for me at full strength. I will probably add peppermint and or spearmint essential oil if I need to continue using the glycerine to maintain the effect and add additional antibacterial effect. Glycerine has a very sweet taste by itself. I also put glycerin on my lips before bed and it has eliminated the 24/7 dry lips that I used to have. I have also used it straight as a mouth rinse followed by a water rinse.
I paid $5.84 for a 16 oz. bottle of "Now Vegetable Glycerine" that is "Food Grade Glycerin" and is easily available from multiple on line supplement suppliers as well as local vitamin stores. I'm sure any brand "food grade glycerin" will work for me if it is full strength.
Check with your doctor first to see if food grade glycerin is something that you can try for night time dry mouth.