7 Best Oral Supplements for Constipation of 2024, According to a GI Dietitian

Where We Stand

If you experience occasional constipation and want a bit more help in improving your stools, try Solgar's Magnesium Citrate. This product is third-party tested, gentle, and effective. If you're experiencing more intense constipation and find yourself backed up, try a stimulant laxative like Senokot; this product contains senna, a natural laxative that promotes contractions of the colon wall and increases colon secretions to add moisture and move things along.

Who Would Benefit from an Oral Supplement for Constipation?

There are many different types of constipation supplements available on the market, and individual responses will vary depending on many factors, such as diet, lifestyle, health status, dosage, and supplement type. Groups that may benefit from a supplement to manage constipation include:

• Those with constipation-predominant irritable bowel syndrome (IBS-C)
• Those with slow-transit constipation* (slow movement in the intestine) due to a diagnosed motility disorder.
• Those with certain types of pelvic floor dysfunction*, such as dyssynergia or muscle weakness, may need extra help with constipation beyond dietary changes and water intake. However, it should be noted that fiber-based supplements may not be best (see below).
• Those who have severe constipation* without impaction or a bowel obstruction.
• Those unable to meet their fiber requirements due to travel or lack of whole food access or are on a low-fiber diet due to a medical circumstance such as a recent surgery.
• Those with active (untreated) diagnosed small intestinal bacterial overgrowth (SIBO), specifically methane-producing bacteria that may cause constipation.
• Those that require medications or supplements from a healthcare professional that may cause constipation, such as:
• High-dose calcium supplementation
• Iron supplementation
• Opioid pain medications 
• Those taking GLP-1 medications. Speak with your prescribing healthcare provider about which supplement for constipation is best for you.
• Those who are pregnant. Speak with a healthcare provider before using any oral laxative supplements, as some are unsafe while pregnant or breastfeeding.

*Note, if you have this type of constipation, you may not respond well to a bulking laxative supplement (see below).

Who May Not Benefit from an Oral Supplement for Constipation

Diet and lifestyle modifications, including gradually increasing dietary fiber, fluids, and movement, are low-cost and relatively simple treatments for common constipation. If you have been unresponsive to these changes or if your constipation is severe or accompanied by other symptoms, consult with a healthcare provider before taking any supplements. Specific types of constipation supplements may not be appropriate for all health conditions.

Oral Laxative Supplements May Not be Beneficial if You:

• Have kidney or cardiac dysfunction: High-dose magnesium supplements (used as osmotic laxatives), in particular, should be avoided or used only under the guidance of a healthcare provider. 
• Take certain medications: Laxative supplements can interfere with some medications, including diuretics and antibiotics, so speak with a healthcare provider about your regimen. 
• Have a bowel obstruction (blockage in the intestine) or fecal impaction (stool that is hardened and stuck): These circumstances require immediate medical attention. 
• Have a history of laxative abuse: Speak with a healthcare provider about treatment for your constipation if you’ve used laxatives excessively in the past. 
• Are on a fluid-restricted diet (many products need to be taken with extra fluid).

Bulking Laxatives (Fiber Supplements) May Not be Beneficial if You:

• Have difficulty swallowing
• Have pelvic floor dysfunction: Adding more bulk when you are unable to efficiently evacuate may add to constipation and discomfort. 
• Have a slow motility disorder such as gastroparesis (delayed stomach emptying), or slow colonic transit 
• Have esophageal stricture (narrowing of the esophagus) 
• Are severely backed up: You may need to consider an osmotic laxative course to clear out excess stool before adding fiber.
• Have active intestinal inflammation such as diverticulitis or active inflammatory bowel disease (IBD), including Crohn’s disease and Ulcerative Colitis.
• Already eat a high-fiber diet: If you get a lot of dietary fiber from the food you eat, too much fiber may worsen constipation.
  

What to Look For

• Evidence-based and Third-party testing: Note that most specific fiber supplements containing the fiber types with the strongest clinical research evidence are not third-party tested and may contain additives. However, they are included here if there is good evidence to support their benefit for regularity. 
• Form: Oral constipation supplements are sold as various types of chemical, herbal, and bulk (fiber) laxatives. Oral constipation supplements typically come in one of the following physical forms:
• Capsules
• Tablets/pills
• Powder
• Chewable/gummy

Powdered products, including some fiber powders and osmotic laxatives, can be added to liquid with no taste or texture change, while others may be artificially flavored or gel with water (you can add these to moist foods to avoid a gooey substance).

There is no research suggesting significant efficacy of one physical form over another, so you may decide based on your taste preferences and convenience. However, keep in mind that some chewable, gummy, or flavored products may contain additional ingredients such as sugar alcohols (e.g., sorbitol, xylitol, erythritol), which can cause extra gastrointestinal symptoms.

• Added Ingredients: Those with food allergies or intolerances should examine all product ingredients and labels, as there may be sources of cross-contamination. 
  

Ingredients & Potential Interactions

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included relative to the recommended daily value of that ingredient. Please bring the supplement label to your healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.

Over-the-counter laxatives are not the same as prescription laxative medications, as prescription medications are FDA regulated and prescribed by a clinician. Check with your healthcare provider before using any over-the-counter laxative product, as they can interact with a variety of medications and supplements. Interactions vary between products and are best verified by your healthcare provider to ensure safety.

Fiber supplements can interact with other medications and reduce or delay their effectiveness. Some medications that interact with these supplements include antidepressants, diabetes medications, and carbamazepine.

Some products may also contain added ingredients such as prebiotics, which can worsen gas and bloating in digestively sensitive people, or sugar alcohols, which can worsen diarrhea. Chewable supplements are more likely to contain one of these ingredients as a sweetener.

Prebiotics (avoid for gas and bloating) include:

• Fructo-oligosaccharides (FOS)
• Inulin (chicory root fiber)

Sugar alcohols (avoid for diarrhea) include:

• Sorbitol
• Mannitol
• Xylitol
• Erythritol

How Much To Take

The dosage of laxative products ranges widely. Talk to a healthcare provider about the appropriate product and dosage for your needs before supplementing. Because of the potential side effects and risk of overdosing on laxative supplements, follow package directions carefully. 

Some products, such as magnesium, may require a larger amount than what is contained in standard doses to attain a laxative benefit. Alternatively, some standard doses may have too strong of an effect for sensitive individuals, and it will be worth trying a smaller dose if that’s the case. In general, there is typically no harm in starting with a smaller (e.g., half-size) dose and increasing it as needed. For fiber supplements, it is typically best to start with a lower serving and increase gradually, along with extra fluids. 

Keep in mind that the majority of supplements are designed for occasional use but may be safe to take for longer periods when directed by a healthcare provider. 

How Much is Too Much?

All laxative supplements can cause serious side effects if used in excess. Common symptoms of laxative overdose include nausea, vomiting, diarrhea, and abdominal cramps. Dehydration and electrolyte imbalance are also potential consequences. Risks vary by specific product as well as individual health status, so it is best to work with a healthcare provider to determine the appropriate dose for you. Some of the product considerations include:

Osmotic laxatives: Osmotic laxatives such as MiraLAX and magnesium are generally considered safe and well-tolerated, though they can cause bloating and/or diarrhea with too large of a dose. Since these types of laxatives draw water into the colon, overusing these products can lead to dehydration and electrolyte imbalances.

Fiber supplements: While there is no Tolerable Upper Intake Level for fiber (the maximum daily amount that can be safely consumed), concentrated doses can cause constipation, gas, or bloating if you add it too quickly or without enough fluids. Most fiber supplements recommend 8 ounces of water with a standard dose, though individual product directions may vary. Inadequate fluid intake can cause the supplement to swell and lead to choking, blockages, or stool impaction, as well as gas, bloating, abdominal pain, and constipation.

Stimulant laxatives: These products are generally recommended as shorter-term treatments for constipation due to their more aggressive nature in the colon (promote contractions), which may cause cramping or diarrhea in sensitive individuals or when taken in too large of a dose. Historically, clinicians have been concerned about these products being habit-forming (i.e., becoming dependent on them to poop), though recent research suggests many of the products available on the market, including Senna, are likely safe for longer-term use.

Tips for Using Oral Constipation Supplements Effectively

A product is most likely to be effective with the following considerations:

• Identify the issue: If you have ongoing constipation that has not responded to diet and lifestyle modification, work with a healthcare provider to further assess the problem. 
  
• Match the problem: Some products that advertise constipation relief can actually make symptoms worse if not matched to your issue appropriately. For example, if your constipation stems from muscle weakness or slow movement in the colon, adding a bulking laxative could further back you up.
  
• Be patient: Since laxative products ultimately affect the colon, it will typically take hours (not minutes!) to see a result. Allow time for it to make its way down the digestive tract, especially before taking more. This is why most products advertise overnight relief.
  
• Start slow: As with any supplement, it’s best to test out your tolerance and response by starting with a lower dosage and slowly increasing it. Consider taking half or less of a standard dose and increasing it as needed.
  
• Minimize cost: You don’t need a designer product or special packaging to obtain the benefits of a research-backed laxative. Look for a product that meets your budget and needs. For products that are sold in powder and capsule form, you may need to take more capsules to equal the same dose of a powdered form (i.e., five capsules versus one scoop of powder), which can make these products more costly.

Experiment with dosage to identify the lowest amount that helps keep you regular to avoid moving through a product unnecessarily quickly. If something is working, it may be worth trying a period without it or with a decreased amount to ensure it is still necessary for you.

• Customize your regimen: Individual responses to laxatives and fiber will vary. It may take experimentation with dosage to optimize results. When it comes to constipation supplements, there is no “one size fits all.”

Our Experts

• Yevgenia Pashinsky, MD, a gastroenterologist specializing in bloating, constipation, pelvic floor dysfunction, and Irritable Bowel Syndrome. 
• Shushy Rita Setrakian, MS, RD, a Registered Dietitian and one of our nutrition and supplement commerce editors. Shushy is passionate about converting nutrition science into meaningful dietary recommendations.

Why Trust Verywell Health

Suzie Finkel, MS, RD, CDN, is a Registered Dietitian specializing in the nutritional management of digestive symptoms and diseases. She holds a master’s degree in nutrition from Columbia University and has trained in numerous clinical gastroenterology settings. As a GI dietitian, she provides evidence-based nutrition services for a wide array of digestive conditions, including chronic constipation and bowel movement irregularities. Her goal is to demystify nutrition (mis)information and facilitate digestive comfort.