A suppository is a small, solid dose of medication designed to be inserted into the body rather than swallowed. Suppositories are typically round, oval, or cone-shaped and made from a shell of gelatin or cocoa butter that melts at body temperature, releasing the active medication inside. They can be inserted into the rectum, vagina, or urethra, depending on the condition being treated.
How Suppositories Work
The outer shell of a suppository is made from materials that stay solid at room temperature but melt once they’re inside the body. Cocoa butter is one of the most traditional bases, and manufacturers also use synthetic fatty bases and waxes. Once inserted, your body heat softens and dissolves the shell over several minutes, allowing the medication to spread across the surrounding tissue.
From there, the medication works in one of two ways. Some suppositories act locally, meaning the drug treats the tissue right where it’s placed. A glycerin suppository for constipation, for example, works by drawing water into the rectum and stimulating a bowel movement, typically within 15 to 60 minutes. A vaginal suppository for a yeast infection delivers antifungal medication directly to the affected area.
Other suppositories are designed for systemic absorption, meaning the medication passes through the lining of the rectum or vagina and enters the bloodstream to treat problems elsewhere in the body. Acetaminophen suppositories for fever work this way. The rectum has a rich blood supply, and drugs absorbed through its lower portion can partially bypass the liver, entering circulation more directly than a pill would. However, this bypass is inconsistent. Studies of rectal acetaminophen have shown up to a ninefold variation in peak drug levels between patients, partly because where the suppository sits in the rectum affects how the drug is processed.
Why Suppositories Are Used Instead of Pills
Suppositories fill a practical gap when swallowing a pill isn’t possible or effective. The most common scenarios include:
- Nausea and vomiting. If you’re actively vomiting, an oral medication won’t stay down long enough to absorb. Anti-nausea suppositories solve this problem directly.
- Difficulty swallowing. Young children, people recovering from surgery, and those with neurological conditions that affect swallowing can receive medication rectally instead.
- Unconsciousness or seizures. Emergency anti-seizure medications can be given rectally when a person can’t swallow safely.
- Local treatment. Conditions like hemorrhoids, anal fissures, inflammatory bowel disease, and vaginal infections are best treated with medication applied directly to the affected tissue.
For children specifically, the rectal route avoids two common challenges with oral medication: kids don’t have to swallow a pill, and the medication doesn’t need to be flavored or taste-masked. This makes suppositories a reliable backup for treating fever or pain in infants and toddlers who refuse or spit out liquid medicines.
Common Types and What They Treat
Rectal suppositories are the most widely known type. They’re used locally to treat constipation (bisacodyl and glycerin suppositories), hemorrhoids, anal fissures, and inflammation from conditions like ulcerative colitis. For systemic treatment, rectal suppositories deliver pain relievers like acetaminophen, ibuprofen, and diclofenac, as well as anti-nausea medications and migraine treatments.
Vaginal suppositories treat infections (yeast infections and bacterial vaginosis), deliver hormonal therapy, and are sometimes used as part of fertility treatments. They’re inserted similarly to a tampon and dissolve over the course of several hours.
Urethral suppositories are far less common. The most well-known example is a small pellet used to treat erectile dysfunction, inserted into the urethra to deliver medication that increases blood flow locally.
How to Insert a Suppository
For rectal suppositories, the recommended position is lying on your left side with your knees bent toward your chest. This follows the natural curve of the lower intestine and makes insertion easier. Remove the wrapper, and insert the suppository as far into the rectum as you comfortably can, using a finger to push it past the muscular ring (the sphincter) at the opening. If it isn’t pushed past this point, the suppository can slip back out. Staying still for a few minutes afterward helps it stay in place and begin dissolving.
Vaginal suppositories are usually inserted while lying on your back with your knees bent, or while standing with one foot raised. Many come with a plastic applicator similar to those used for tampons. Wash your hands before and after, and try to insert it before bed so gravity and movement don’t cause it to slip out prematurely.
How They Compare to Oral Medication
Suppositories are not simply interchangeable with pills. Rectal absorption tends to be slower and less predictable than oral absorption. A meta-analysis comparing oral and rectal acetaminophen found that the rectal version takes longer to reach peak levels in the blood and often fails to achieve the same therapeutic concentration. The recommended dosing interval reflects this: rectal acetaminophen is typically given every 6 to 8 hours rather than the 4 to 6 hours used for oral doses.
That said, for local conditions like constipation or hemorrhoids, suppositories are often more effective than oral alternatives because they deliver medication exactly where it’s needed at a much higher concentration than a pill could achieve after passing through the entire digestive system.
Side Effects and Practical Concerns
The most common side effect of rectal suppositories is mild burning or irritation at the insertion site. Laxative suppositories can also cause stomach cramps, and in rare cases, rectal bleeding. If bleeding occurs, stop using the suppository. Vaginal suppositories can cause local irritation, discharge, or a mild burning sensation as the medication dissolves.
Leakage is a practical annoyance with both rectal and vaginal types. Some residue from the melted base may leak out after insertion, which is normal but inconvenient. Wearing a panty liner can help with vaginal suppositories, and lying still for 15 to 20 minutes after inserting a rectal suppository reduces the chance of it coming back out before the medication absorbs.
Storage Tips
Because suppositories are designed to melt at body temperature, they’re sensitive to heat. Most should be stored at room temperature between 59 and 77°F, and some require refrigeration between 36 and 46°F. Check the label on your specific product. If a suppository feels unusually soft, looks misshapen, or has changed color, it may have partially melted and resolidified, which can alter how the medication releases. In that case, don’t use it. During warm weather, storing suppositories in the refrigerator for a few minutes before use can make them firmer and easier to insert.