Fiber supplements are generally considered safe, but people with certain medical conditions may want to avoid them.

Most studies don’t specify a particular timing.

The most important factor is taking them every day (regardless of timing).

A person mixing psyllium fiber into a glass of water

Svetlana-Cherruty / Getty Images

Whether or not the timing was key to the weight loss effect is unclear.

Fiber can help you feel fuller during the day so that you may eat fewer calories.

Consider what time of day you feel hungry and work your fiber intake around that time.

Weight loss:Taking fiber in the evening (around dinnertime) could also help reduce late-night snacking.

Should You Take Fiber Supplements Before or After Meals?

Taking a fiber supplement before or after a meal will depend on your reason for taking it.

Taking fiber before a meal may help with weight loss.

Taking fiber supplements with a meal may help manageblood glucose levels.

A gel-forming soluble fiber supplement taken with a meal may also help stabilize blood glucose levels after eating.

There’s little evidence that taking fiber supplements after a meal can prevent gas and bloating.

If intestinal symptoms are an issue for you, try different supplements to determine what works best for you.

Timing of Fiber and Medications

Some types of fiber slow down the digestive process.

That could affect drugs such as warfarin, antibiotics, metformin, and Tylenol (acetaminophen).

It’s recommended that people take drugs an hour before or two hours after the fiber supplement.

This works out to 14 grams of fiber for every 1,000 calories of food.

As calorie needs differ, so does the amount of fiber.

People with intestinal strictures (narrowing of the intestine) should avoid fiber supplements.

However, ahigh-fiber dietis recommended for people with diverticular disease when they are not inflamed.

Whenchoosing a supplement, look for products independently tested or certified by organizations such asNSF,U.S.

Pharmacopeia (USP), orConsumerLab.com.

2017;29:216-223. doi:10.1002/2327-6924.12447

Konsyl Pharmaceuticals, Inc.Best way to take fiber supplements.

2022;116:953-969. doi:10.1093/ajcn/nqac184

Harvard Health.Laxatives: what to know about choosing the right one.

Oregon State University Linus Pauling Institute.Fiber.

Quagliani D, Felt-Gunderson P.Closing Americas fiber intake gap.Am J Lifestyle Med.

2016;11(1):80-85. doi:10.1177/1559827615588079

Harvard Health Publishing.The facts on fiber.

U.S. Department of Agriculture and U.S. Department of Health and Human Services.Dietary Guidelines for Americans, 2020-2025.

U.S. Department of Agriculture.

Ask USDA.How much (dietary) fiber should I eat?