Glycerol is a naturally occurring chemical. People use it as a medicine. Some uses and dosage forms have been approved by the U.S. Food and Drug Administration (FDA).
Glycerol is taken by mouth for weight loss, improving exercise performance, helping the body replace water lost during diarrhea and vomiting, and reducing pressure inside the eye in people with glaucoma. Athletes also use glycerol to keep from becoming dehydrated.
Healthcare providers sometimes give glycerol intravenously (by IV) to reduce pressure inside the brain in various conditions including stroke, meningitis, encephalitis, Reye's syndrome, pseudotumor cerebri, central nervous system (CNS) trauma, and CNS tumors; for reducing brain volume for neurosurgical procedures; and for treating fainting on standing due to poor blood flow to the brain (postural syncope).
Some people apply glycerol to the skin as a moisturizer.
Eye doctors sometimes put a solution that contains glycerol in the eye to reduce fluid in the cornea before an eye exam.
Rectally, glycerol is used as a laxative.
How does it work?
Glycerol attracts water into the gut, softening stools and relieving constipation.
Likely Effective for:
- Constipation, when used rectally as a suppository.
Possibly Ineffective for:
- Helping with weight loss, when taken by mouth.
Likely Ineffective for:
- Improving exercise performance when taken by mouth.
- Treating acute stroke when used intravenously.
- Helping maintain the body's water levels (hydration) in athletes and people with intestinal problems.
- Wrinkled skin.
- Other conditions.
Side Effects & Safety
Glycerol seems to be safe for most adults. When taken by mouth, glycerol can cause side effects including headaches, dizziness, bloating, nausea, vomiting, thirst, and diarrhea.
Glycerol may not be safe when injected intravenously (by IV). Red blood cells might get seriously damaged.
Special Precautions & Warnings:Pregnancy and breast-feeding: Not enough is known about the use of glycerol during pregnancy and breast-feeding. Stay on the safe side and avoid use.
The following doses have been studied in scientific research:
- As an adult laxative for constipation: The common dose of glycerol is a 2-3 grams in suppository form or a 5-15 mL enema. For children younger than six years old, the dose is a 1-1.7 grams as a suppository or a 2-5 mL enema.