Glycerin Suppositories: How Do They Work?

Glycerin suppositories are indicated for relieving symptoms of temporary and occasional constipation for adults and adolescents 12 years of age and older.
Glycerin Suppositories: How Do They Work?
María Vijande

Reviewed and approved by the pharmacist María Vijande.

Written by María Vijande

Last update: 27 May, 2022

Generally, people use glycerin suppositories to solve occasional constipation. Doctors recommend them to treat this condition because they act quickly and directly.

Glycerol is the active ingredient in glycerin suppositories. It’s a substance that exerts its laxative action when administered rectally. This effect is achieved because when the suppositories are administered, the stool softens and produces a mild local irritating effect, stimulating intestinal peristalsis.

How do glycerin suppositories work?

As we mentioned, the effect of glycerin suppositories is due to a two-fold action:

  • Local irritant effect on the rectal mucosa: the irritant effect doesn’t affect the intestinal walls. It causes the contraction of the rectum promoting the expulsion of stool.
  • Osmotic effect: glycerol absorbs water and this, together with its lubricating properties, softens the stool and facilitates its expulsion.

Glycerin suppositories take effect from 15 minutes to an hour after their application. Furthermore, your body doesn’t absorb glycerol it’s almost entirely eliminated with the feces.

Woman sitting on toilet constipated, holding stomach.


Doctors recommend glycerin suppositories for relieving occasional constipation in adults.

What is constipation?

In general, constipation is when the frequency of passing stools decreases. Constipation is a symptom that means that intestinal transit is decreased for some reason.

Constipation affects more women than men, especially women between the ages of 20 and 35 and after the age of 60.

Depending on how long it lasts, constipation can be classified into two types:

  • Occasional: this may be due to changes in diet and water consumption, lack of exercise, treatment with certain medications, or stressful situations.
  • Chronic: for doctors to consider constipation chronic, it must last at least 3 months.

Chronic constipation can be related to situations that are similar to those of occasional constipation but that lasts longer. However, other times, it’s due to digestive problems and certain diseases.

Do glycerin suppositories have side effects?

An x-ray showing inflamed colon, a possible side effect of excess glycerin suppositories.

If you use glycerin suppositories in excess or for long periods of time, they can cause irritable bowel syndrome. In addition, you can sometimes experience symptoms such as itching, stinging, and irritation in the rectal area.

However, the use of glycerin suppositories is contraindicated if you’re allergic to glycerol. You also shouldn’t use them if you have hemorrhoids, symptoms of intestinal obstruction, appendicitis, or other intestinal diseases.

What are the advantages of using them?

There are three main advantages of using glycerin suppositories:

  • Effective relief of occasional constipation.
  • Speed.
  • Local action.

In general, the usual dose in adults is one suppository a day, and you shouldn’t use them for more than 6 or 7 days in a row.


Glycerin suppositories have some contraindications, among which are the following:

  • Hypersensitivity to any of its components.
  • Gastrointestinal transit disorders: you shouldn’t take them if you suffer intestinal transit disorders such as if you suffer from intestinal obstruction.
  • Existence of abdominal pain of unknown origin: if you experience abdominal pain with no known cause, you shouldn’t use these suppositories until you know the origin of the pain. The use of laxatives in these situations can hide an underlying condition that’s still unknown.

In addition, the use of glycerin suppositories is contraindicated when you have a condition that carries a certain danger if intestinal peristalsis is stimulated.

You should only use Glycerin suppositories occasionally

Glycerin suppositories allow you to alleviate the problem of occasional constipation directly and quickly. However, before starting constipation treatment, you should try to alleviate it by modifying your habits.

Finally, it’s important to remember that suppositories don’t solve the root of constipation. They only relieve the symptoms quickly and temporarily. Therefore, don’t hesitate to consult your doctor if you suffer from constipation regularly.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Buitrago Navarro, J., Albendin Garcia, L., Toledo Calvo, L., & Martos García, R. (2015). ABORDAJE DEL ESTREÑIMIENTO EN LACTANTES POR PERSONAL DE ENFERMERÍA EN UN DCCU. Nutricion Clinica y Dietética Hospitalaria.


  • Farmacéutica. (2009). Farmacia Empresa Información de mercado MARIA-JOSEP DIVINS. 32 Farmacia Profesional.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.