What Is a Suppository? Types, Uses and How They Work

A suppository is a single dose of a drug or other ingredient mixed into a base (cocoa butter, hard fat, glycerin or polyethylene glycol) and formed into a shape that can be inserted into a body opening. Once inside, the base either melts at body temperature or dissolves in the small amount of fluid present, releasing the ingredient. That is the whole mechanism. Nothing is swallowed, nothing passes through the stomach, and for local problems the ingredient works exactly where the trouble is.

On the shelf you will meet three shapes. The rectal bullet is a tapered cylinder about an inch long, usually wrapped in foil or plastic; glycerin, bisacodyl, hemorrhoidal and acetaminophen suppositories all take this form. The vaginal ovule or capsule is an egg-shaped insert or a two-piece capsule filled with powder; miconazole ovules and boric acid capsules are the common examples, and many come with or need an applicator. The pre-filled liquid applicator is glycerin in a small squeeze bottle with a soft tip, sold as Fleet Liquid Glycerin Suppositories, for people who find a solid awkward to handle. Urethral suppositories exist but are prescription products and are not part of this site.

Laxative suppositories are the largest group. Glycerin suppositories are hyperosmotic: they draw water into the lower bowel and soften the stool that is already there. The Fleet Glycerin Drug Facts label states glycerin 2 g per adult suppository, lists the use as relief of occasional constipation, states that it generally produces a bowel movement in 15 minutes to 1 hour, and directs one suppository daily for ages 6 and over, with children under 6 sent to a doctor. Bisacodyl suppositories such as Dulcolax are stimulant laxatives: 10 mg of bisacodyl acts on the bowel wall itself, the label carries the same 15 minutes to 1 hour window, and it is explicit that stimulant laxatives are for occasional use. The full ranking is in the best suppositories for constipation, and the two mechanisms are compared head to head in glycerin vs bisacodyl.

Hemorrhoidal suppositories are for internal hemorrhoids. The Preparation H suppository label lists cocoa butter as a protectant and phenylephrine as a vasoconstrictor; its uses are temporary relief of itching, burning and discomfort and temporary shrinking of hemorrhoidal tissue, and its directions cap use at up to 4 times daily. Every hemorrhoidal label carries the same stop line: if bleeding occurs, or the condition worsens or does not improve within 7 days, stop and ask a doctor. Acetaminophen suppositories (FeverAll) are fever and pain reducers for children who cannot keep oral medicine down, in 80 mg infant, 120 mg children's and 325 mg junior strengths, each labeled by age. The infant strength is labeled for 6 to 36 months and sends babies under 6 months to a doctor, and the American Academy of Pediatrics says any fever in an infant under 3 months is a call to the doctor, not a dose.

The vaginal shelf is where the word suppository gets stretched, so the legal categories matter. OTC antifungals (miconazole in Monistat, clotrimazole in Gyne-Lotrimin and generics) are FDA-regulated drugs with a Drug Facts label whose stated use is treating vaginal yeast infections. The Monistat label directs one ovule at bedtime for the stated number of nights, says to ask a doctor before use if this is your first vaginal yeast infection or if infections recur, and says to ask a doctor if symptoms do not improve in 3 days or last more than 7. That is the only vaginal suppository category on this site with an approved treatment claim.

Boric acid suppositories are not FDA-approved to treat any condition. The labels describe them as for vaginal odor or pH balance support, and we describe them the same way. Every box carries the same warnings and this page repeats them: for vaginal use only, never taken by mouth because boric acid is poisonous if swallowed, keep away from children, do not use if pregnant or nursing, do not use on broken skin, stop and see a clinician if symptoms persist, and see a clinician for a diagnosis before self-treating. Probiotic, vitamin E, tea tree and hyaluronic acid inserts are dietary supplements or cosmetics: they moisturize or support comfort, and they do not treat, cure or prevent anything. These statements have not been evaluated by the Food and Drug Administration. The shelf is ranked in the best vaginal suppositories, and the boric acid guide carries the full safety note.

Two things happen after insertion, and which one depends on the base. Fat-based suppositories (cocoa butter, hard fat, hydrogenated vegetable oil) melt at roughly body temperature; cocoa butter's melting point sits in the low to mid 90s Fahrenheit, which is why a hemorrhoidal suppository that felt firm from the refrigerator is liquid within minutes of insertion. Water-soluble bases (glycerin with sodium stearate, polyethylene glycol) dissolve in the small volume of fluid present rather than melting, which is why a glycerin suppository still works in a cool room and why several labels tell you to moisten it with water before inserting.

What the ingredient does next is local or systemic. A glycerin laxative works locally: it draws water into the rectum and the effect is a bowel movement. A hemorrhoidal suppository coats and constricts tissue where it sits. Acetaminophen is different: it is absorbed through the rectal lining into the bloodstream, which is the whole point for a vomiting child. The practical consequence for every type is the same: stay lying down for the minutes the label or the pharmacist suggests so the melted base is not expelled before it has done its job, and for a laxative, be near a bathroom. Step-by-step technique is in how to insert a suppository, and timing by type is in how long a suppository takes to work.

The table below lines up the common OTC forms by what each Drug Facts label states about time. It is the fastest way to see why a suppository exists: for constipation, nothing oral is labeled under 6 hours, and nothing rectal is labeled over 1 hour.

Two decisions fall out of the table. If you need a bowel movement soon, the choice is between a suppository and an enema, which our suppository vs enema page settles by situation. If you can wait overnight or longer, the oral products are simpler; suppository vs oral laxative lays out that trade.

Every product in this article is sold with a label that tells you when to stop, and the lines are consistent enough to memorize. Laxatives (glycerin, bisacodyl, enemas): ask a doctor before use if you have stomach pain, nausea or vomiting, or a sudden change in bowel habits lasting over 2 weeks; stop use and ask a doctor if you have rectal bleeding or fail to have a bowel movement after use, because either can be a sign of a serious condition; and do not use laxative products for more than 1 week unless directed by a doctor. Hemorrhoidal products: stop and ask a doctor if bleeding occurs or the condition does not improve within 7 days. Acetaminophen: stop and ask a doctor if fever gets worse or lasts more than 3 days, and for an infant under 3 months, the AAP's guidance is to call the doctor before doing anything else.

Vaginal antifungals: ask a doctor before use for a first yeast infection or recurring ones, and if symptoms do not improve in 3 days or last more than 7. Boric acid: vaginal use only, never by mouth, not in pregnancy, and see a clinician for a diagnosis rather than guessing. For a child of any age, the pediatrician decides which product and whether to use one at all; suppositories for babies and toddlers reports what each label states about ages.