How long does it take for Phillips laxatives to work?

How fast do laxatives work and how long do they last?

If you buy via a link on this site, for example, we may earn a small commission. How it works. Laxatives are a type of medication that is used to treat


If you buy something through a link on this page, we may earn a small commission. How it works.

What are laxatives?

Laxatives are a type of medication that can be used to treat constipation. Laxatives do this by stimulating bowel movements.

There are many different types of laxatives. Different types of laxatives work in different ways, start working at different times, and stay in the body for different lengths of time.

We explain the differences in the duration of each type of laxative as well as further information on the individual types of laxative.

Time schedule

The table below shows how long it takes for each type of laxative to work. Of the different types, suppositories work the fastest between 15 and 30 minutes.

Type of laxativeHow long does the work take?
Softening12 to 72 hours
Mass formation12 to 24 hours (some effect)
48 to 72 hours (full effect)
lubricant6 to 8 hours
Hyperosmotic48 to 72 hours (lactulose)
30 minutes to 3 hours (saline solution)
6 hours or more (polymer)
stimulant6 to 12 hours
Suppositories15 to 30 minutes

The time a drug spends in your system can depend on the active ingredient, the dose given, and the way it leaves the body.

Sometimes this information is expressed as a drug half-life or the time it takes 50 percent of the drug to leave your system.

The active ingredients of laxatives can have different half-lives. For example, the half-life of lactulose is about 2 hours while the half-life of bisacodyl is 16 hours. Bulky laxatives have no half-life as they will be eliminated the next time you have a bowel movement.

If you are concerned about the time a laxative spends in your system, it is worth raising your concerns with a doctor or pharmacist.

Emollient laxatives

Emollient laxatives are also known as stool softeners.

Plasticizers take 12 to 72 hours to work. They make your stool softer by adding moisture to it. Softer stools are easier to pass.

The active ingredient in emollient laxatives is a compound called docusate.

Examples of emollient laxative products are Colace and Surfak.

Buy stool softeners here.

Bulking laxatives

Bulky laxatives work much like the fiber you get from your diet.

They promote the absorption of water into your intestines. This makes the chair bigger and softer which in turn makes it easier to pass.

They need 12 to 24 hours for a certain effect and 48 to 72 hours for their full effect.

The active ingredients of bulking laxatives may include psyllium, methylcellulose, and sterculia.

Examples of mass-building laxatives are Metamucil and Benefiber.

Here are options for purchasing mass building laxatives.

Lubricant laxative

Lubricants Laxatives promote bowel movement by covering the stool with a waterproof film. This allows the stool to hold onto its moisture as well as move more easily through the intestines.

The effects of lubricant laxatives last 6 to 8 hours.

Mineral oil is an example of a laxative lubricant.

You can buy mineral oil here.

Hyperosmotic laxatives

Hyperosmotic laxatives work by increasing the amount of fluid in your bowel. This increase in fluid can help soften the stool and promote its passage through the intestines.

There are several types of hyperosmotic laxatives that are divided according to active ingredient.


The active ingredient in lactulose laxatives is a sugar-like compound.

Lactulose laxatives are widely used to treat long-term or chronic constipation. This type takes 48 to 72 hours.

Examples of lactulose laxatives include enulose and generlac.

Saline solution

These laxatives are made up of salts in liquid. They are used for the short-term treatment of constipation.

Working with saline solution takes 30 minutes to 3 hours. Examples of saline laxatives are Phillips' Milk of Magnesia and Royvac.


Polymer laxatives are made up of large molecules like polyethylene glycol. Polymer laxatives, like saline laxatives, are used for the short-term treatment of constipation.

Examples of polymer laxative products include MiraLAX and PegaLAX. Polymers take 6 hours or more to work.

See your options for hyperosmotic laxatives.

Stimulant laxatives

Stimulant laxatives cause the muscles of your intestines to contract. This will make it easier for stool to pass through your intestines.

This type of laxative can last 6 to 12 hours.

The active ingredients of laxatives may include senna, bisacodyl, and sodium picosulfate.

Examples of stimulant laxatives include Dulcolax and Ex-Lax.

You can find a laxative to buy here.


A suppository is a medicine that is inserted into your rectum. Once inserted, the drug dissolves and enters the bloodstream.

Depending on the active ingredient, suppositories can either soften the stool or stimulate the intestinal muscles to make stool movement easier.

Suppositories work the fastest within 15 to 30 minutes.

The active ingredients bisacodyl and glycerin can be given as suppositories to treat constipation.

Examples of available suppository medications include Dulcolax and Fleet Glycerin.

Buy suppositories here.

A word of caution

There are some risks that you should be aware of when using laxatives. These can be:

Dehydration or electrolyte imbalances

Since many laxatives draw water into your intestines, you should drink plenty of water while taking them. If you don't, you can become dehydrated or develop an electrolyte imbalance.

Drug interactions

Read the labels carefully when choosing a laxative. Some medications, such as antibiotics and heart medications, can negatively affect laxatives.

If you are not sure which laxative to take, ask your doctor.

Decrease in intestinal motility

Frequent use of laxatives can cause natural bowel movements to malfunction.

You should always make sure to use laxatives in moderation. If you find that you have to use laxatives frequently to have a bowel movement, you should see your doctor to discuss your concerns.

Pregnancy and Breastfeeding Considerations

If you are pregnant, you should speak to your doctor before using laxatives. Some laxatives, such as stool softeners or bulk laxatives, are safe for pregnant women and others are not.

Most laxatives are safe to use while breastfeeding. However, you should speak to your doctor before use.

Some laxatives can be passed on to the child through breast milk and cause diarrhea.

The final result

There are a variety of laxatives available to treat constipation. Some laxatives are better for treating constipation in the short term, while others are better for treating long-term or chronic constipation.

You should always consult your doctor if you are unsure about which laxative to use for your constipation.

You can also help prevent constipation by following some of the tips below:

Increase fiber intake

Increase the amount of fiber in your diet. Fiber helps improve bowel function.

Make sure you get enough fruits, vegetables, and whole grains. Here are 22 high fiber foods that you should be eating.

Drink enough

Having enough fluids can make bowel movements easier.

You should aim for 8 glasses of water a day while avoiding things like caffeine and alcohol. Here are 16 reasons to drink more water.

Be active

Making sure that you exercise regularly will help the stool move through your bowels more effectively. Here are 6 ways to live a more active life.

Don't hold it

If you feel like you need to have a bowel movement, leave as soon as possible. Don't hold onto it.