Losing weight requires eating a balanced, low-calorie diet and adopting an active lifestyle. With time, you may see the number on the scale go down. But if your weight loss efforts aren’t working, one of the best over-the-counter weight loss pills may give you extra support. If not, you may consider a medically supervised weight loss program.

Over-the-counter (OTC) weight loss medications are available at drugstores, health food stores, grocers, and online. You can buy them without a prescription and use them on your own according to the instructions on the package. Still, talk to your doctor if you’re considering taking any supplement — whether a medication, herbal, OTC, pill, powder, or something else.

To help guide your conversation, in this guide, we cover:

What are the best OTC weight loss pills?
Which over-the-counter weight loss pills work best?
What to know about the side effects of OTC weight loss pills
What to do if OTC weight loss pills don’t work for you
How to find a professional weight loss provider

What are the best OTC weight loss pills?

OTC weight loss pills support weight loss in different ways. Some decrease appetite. Others reduce how much fat you absorb. In any case, you may have better luck losing weight by adding an OTC diet pill to your plan after talking to your healthcare provider.

Following are some of the top OTC weight loss pills.

Alli (orlistat)

Alli is the only over-the-counter medication that’s U.S. Food and Drug Administration (FDA)-approved for weight loss. It was approved in 2007 for weight management in overweight adults (18+) in conjunction with a low-fat, low-calorie diet. Orlistat, the active ingredient in Alli, is also available at a higher dose by prescription as the brand name Xenical.

How it works: Alli (orlistat) works by blocking the absorption of roughly 25% of fat in the foods you eat. By preventing fat from being absorbed, you naturally take in less fat and fewer calories.

How to take it: Alli comes in a 60-milligram capsule you take 3 times a day within an hour of each meal. The meals you take with Alli should include around 15 grams of fat. The manufacturer also recommends taking a multivitamin that includes fat-soluble vitamins (vitamins A, D, E, K, and beta carotene) once a day at bedtime while on Alli.

Effectiveness: One study found that users taking orlistat compared to those just dieting lost on average 5.5% of their starting weight over 24 weeks. 2.9% is 16.5 pounds for a 300-pound person.

Cost: At the time of publication, drugs.com shows a retail price for Alli of $55.82 for 90 capsules or a 1-month supply.

Common side effects: Orlistat can cause a few side effects, primarily involving the digestive system. You might experience oily stools or discharge, frequent bowel movements, or gas while taking Alli.

Garcinia cambogia

Garcinia cambogia extract is a popular supplement for weight management. Garcinia cambogia is a plant native to India and Southeast Asia. Garcinia cambogia supplements are made from the fruit pulp and rinds of the plant. The active chemical in Garcinia cambogia is hydroxycitric acid (HCA).

How it works: HCA supports weight loss due to its anorexigenic effect (loss of appetite), increased fat oxidation (breakdown), and regulation of endogenous lipid biosynthesis (turning fat into energy).

How to take it: Garcinia cambogia extract is available in several forms, including capsules, tablets, powders, and liquids. Follow the instructions on the product label if taking it.

Effectiveness: A meta-analysis of the effects of HCA used for obesity found a small, but statistically significant difference in weight loss when using HCA instead of a placebo. Though gastrointestinal adverse events were twice as common in the HCA group compared with the placebo group, the analysis concluded that Garcinia extracts/HCA can lead to short-term weight loss. Note that the amount was small and the clinical relevance uncertain.

Cost: The cost of garcinia cambogia supplements is roughly $16 for 120 capsules, which is about a 60-day supply. Costs vary by brand and store.

Common side effects: Side effects from Garcinia cambogia are generally mild and can include upset stomach, diarrhea, dry mouth, and headaches. Some uncommon, but sometimes severe cases of liver damage have been associated with the use of Garcinia cambogia products and products containing only Garcinia cambogia or both Garcinia cambogia combined with other ingredients.

Hydroxycut

Hydroxycut is the brand name for an herbal weight loss supplement that contains Robusta coffee extract from Coffae canephora robusta, essentially green coffee beans or green coffee extract (GCE).

In its original formula, Hydroxycut was banned in 2004 for severe side effects and later recalled for toxicity. Hydroxycut products were reformulated and are available today with different ingredients. Ephedra, a stimulant in the original formula, is no longer used in Hydroxycut products.

How it works: Hydroxycut’s active ingredient is Robusta coffee extract, which includes caffeine and antioxidants known as chlorogenic acids that are described as energizing and able to suppress appetite for a short time. There isn’t adequate evidence that other Hydroxycut ingredients, such as cayenne pepper, help with weight loss.

How to take it: Hydroxycut products come in multiple forms, including pills, capsules, chews, and shakes. People under age 18 shouldn’t take Hydroxycut supplements. When taking Hydroxycut, follow a low-calorie diet and regularly exercise.

Effectiveness: The effectiveness of Hydroxycut is backed by 2 separate scientific studies. In one 60-day study, people who took the key ingredient in Hydroxycut lost 10.95 pounds compared to those taking a placebo who only lost an average of 5.40 pounds. Both groups followed a low-calorie diet during the study.

In a different 8-week study, people using Coffae canephora robusta lost 3.7 pounds, while those on a placebo lost 1.25 pounds. Both groups in this study also followed a reduced-calorie diet and did moderate exercise.

Cost: You can buy a 72-count bottle of oral Hydroxycut Original for $27.99. Costs vary by brand and store.

Common side effects: Some Hydroxycut users report headaches, excessive sweating, jitters, and nausea. In rare cases, Hydroxycut products have caused compartment syndrome, which causes muscle pain from pressure buildup in your muscles. Rhabdomyolysis, another rare complication, happens when damaged muscles release proteins in the blood, which can damage the heart and kidneys. There’s some evidence of Hydroxycut causing liver damage.

Conjugated linoleic acid (CLA)

CLA is a fatty acid that may support weight loss when taken as a supplement. Most CLA in supplements comes from safflower oil instead of other common sources, like dairy and beef.

How it works: CLA may support weight loss by promoting the breakdown of fat while slowing fat accumulation.

How to take: CLA supplements are available as capsules, softgels, powders, and liquids. You can take CLA as a supplement before or during meals. CLA also occurs naturally in foods, such as meat and dairy. When taking a supplement, read the package to understand how to take it and to understand the safety information.

Effectiveness: There’s mixed evidence for CLA’s effectiveness in supporting weight loss, though some research suggests it can reduce fat mass and support muscle growth simultaneously. Some research also suggests that taking CLA alongside exercise causes more fat loss than exercise alone, more research is needed to confirm this finding.

Cost: A 180-count bottle of 800 milligrams of CLA softgels costs just under $19. Costs vary by brand and store.

Common side effects: CLA side effects are rare but can happen when large doses are consumed. They include digestive symptoms, such as nausea, constipation, stomach pain, and vomiting. People on blood pressure medications should only take CLA with the guidance of a doctor due to potential side effects in people taking blood pressure drugs.

OTC fat burners or “phentermine” alternatives

Phentermine is available as a short-term prescription medication for weight loss. A few over-the-counter nutritional supplements are also sold as phentermine alternatives. They do not, however, contain phentermine and instead, contain a mix of amino acids, herbs, and other ingredients. A few of the most popular are PhenQ, PhenGold, and Phen 24.

How they work: PhenQ claims to target 5 areas of metabolic health to potentially help people lose excess fat, reduce cravings, and improve energy.

PhenGold claims to blend research-backed ingredients that make it a natural fat burner and weight loss aid.

Phen24 also claims that its natural ingredients reduce cravings, burn fat, and increase energy.

How to take it: PhenQ, PhenGold, and Phen 24 are oral tablets. PhenQ is taken twice a day with water and a meal. A single dose of PhenGold, 3 capsules, is taken before breakfast every day. Phen 24 comes in a day formula and a night formula. The day formula is taken as one capsule every morning with breakfast. The night formula dosage is two capsules, taken 15 minutes before dinner. The Phen 24 day and night formulas target different functions to promote faster weight loss, so you could use them at the same time.

Effectiveness:

Cost: These supplements cost around $30 for 60 capsules. Costs vary by brand and store.

Common side effects and warnings: Side effects for these supplements vary. If you choose to take one of them, see each package’s label for warnings and contradictions and consult with a licensed healthcare professional first. Don’t take them if you’re pregnant or breastfeeding.

PhenGold and PhenQ both contain caffeine. If you’re sensitive to caffeine or experience shaking, dizziness, headaches, or other caffeine-related side effects, don’t consume caffeine from other sources while taking the product and or avoid other sources of caffeine entirely.

Bitter orange

Bitter orange, also called Seville orange or marmalade orange, is a supplement derived from a fruit-bearing tree native to Southeast Asia (Citrus aurantium) and marketed for weight loss. It contains a natural chemical called p-Synephrine which may support fat loss. It also acts as a natural stimulant.

How it works: Synephrine is believed to increase energy expenditure and the breakdown of fat and reduce appetite.

How to take it: Most supplements containing bitter orange are capsules or powders. Follow the instructions on the label if you choose to take one.

Effectiveness: Research suggests p-Synephrine may support increased fat burning during low- to moderate-intensity exercise, though further research is needed on its overall effect on weight loss. Research on the safety and effectiveness of weight loss pills with p-Synephrine is lacking.

Cost: Bitter orange supplements cost around $20 for a 200-day supply. Costs vary by brand and store.

Common side effects: A meta-analysis of research studies indicated that prolonged bitter orange use can elevate blood pressure and raise heart rate. It may also cause fatigue. The National Collegiate Athletic Association (NCAA) lists synephrine (bitter orange) as a stimulant and includes it on its list of banned drugs.

Acacia fiber

Acacia gum or fiber comes from the powdered tree sap of the Acacia Senegal tree native to the Sahel region of Africa. It’s also known as gum arabic. As a dietary supplement, it expands in your stomach to increase feelings of fullness — a mechanism similar to prescription Plenity which is an FDA-cleared weight loss management aid taken as an oral capsule that contains cellulose and citric acid.

How it works: Acacia fiber supplements may help you feel full, so you can eat less. They may also help lower blood sugar levels.

How to take it: Over-the-counter acacia fiber supplements come in different formulations, including powders you can mix into beverages or capsules you take orally. When taking any acacia or other supplement, follow the dosing instructions on the label. And when starting acacia fiber supplements, start with a small dose and build up to a higher one over time to minimize side effects, like bloating, diarrhea, and nausea.

Effectiveness: Participants in a study of acacia gum reported feeling more satiated after meals than participants not taking it. Acacia fiber may also lower blood glucose to help prevent or manage type 2 diabetes.

Cost: In powder forms, acacia fiber costs $20 to 30 for a 2.5-pound package. Capsules run around $25 for a 300-count supply. Costs vary by brand and store.

Common side effects: One study found Acacia gum to be well tolerated by most participants. It can cause bloating, diarrhea, and nausea for some people. Acacia fiber is an FDA-approved food additive and is generally recognized as safe (GRAS).

Glucomannan

Glucomannan is a water-soluble, fermentable dietary fiber available as a supplement for weight loss. It comes from the root of the elephant yam also known as konjac (Amorphophallus konjac or Amorphophallus rivieri) found in Southeast Asia and India.

How it works: Glucomannan may support weight loss because it absorbs water and takes up space in your stomach, which leaves little room for a hefty appetite. As a dietary fiber, it also reduces protein and fat absorption in your intestines.

How to take it: The recommended dose of glucomannan is 1 gram, 3 times a day in powder form. You should take glucomannan before each meal to optimize its weight loss benefits.

Effectiveness: People taking glucomannan regularly have reported modest weight loss. Research suggests glucomannan offers additional health benefits like lowering cholesterol and glucose in people with type 2 diabetes.

Cost: An 8-ounce supply of glucomannan powder costs $15 to $20. Costs vary by brand and store.

Common side effects: Glucomannan is generally safe but can cause mild side effects, such as bloating, flatulence, and diarrhea. You should take it with water to avoid choking as it may expand in your throat before it reaches your stomach.

Guarana

Guarana is an herbal weight loss supplement and an ingredient in many energy drinks. It comes from Guarana (Paullinia cupana), a plant native to the Amazon region. Guarana contains a high amount of natural caffeine and theophylline and theobromine, which are chemicals similar to caffeine.

How it works: Guarana’s caffeine content is 2 to 8%, which is higher than coffee beans, which contain 1 to 3%. This makes it a mild appetite suppressant, which can help people follow a reduced-calorie diet. It also acts as a mild diuretic, which may reduce water weight. Because of its high caffeine content it may be unsafe if consumed in large quantities.

How to take it: Guarana supplements come in several different forms, including pastes and powders. The recommended dose is typically 1 gram dissolved in water or juice. Follow the instructions on the label of any supplement you try.

Effectiveness: Guarana shows promising evidence of improving metabolism and reducing inflammation, though further studies are needed.

Cost: Guarana powder costs $15 for 100 servings while oral forms cost around the same for a 100-count supply. Costs vary by brand and store.

Common side effects: In high dosages, guarana can cause side effects such as nervousness, insomnia, the jitters, and dehydration. Because of its high caffeine content and other components, it can have many other side effects and interact with medications.

Saffron extract

Saffron is a flower harvested from Crocus sativus L., a medicinal plant. The flower is used to make saffron the spice. Saffron extract is also used in over-the-counter weight loss supplements. It’s rich in antioxidants and may offer other health benefits beyond supporting weight loss, including reducing inflammation. Widespread inflammation contributes to chronic disease, pain, fatigue, frequent infections, and other serious health complications.

How it works: Saffron extract may support weight loss by suppressing appetite to make it easier to avoid overeating and follow a reduced-calorie diet.

How to take it: Saffron extract supplements come in capsules taken by mouth. You can take 1.5 grams daily based on the instructions on the product’s label.

Effectiveness: Research suggests saffron extract can curb hunger to reduce dietary intake and may have promise as an anti-obesity drug.

Cost: The costs of saffron capsules range from $12 to more than $50 for a 2-month supply. Costs vary by brand and store.

Common side effects: Side effects from saffron extract can include nausea, headaches, and vomiting. But some studies indicate it has no side effects.

Guar gum

Guar gum comes from soaking the seeds of guar plants, either Cyamopsis tetragonoloba or Cyamopsis psoraloides. The gum is used in weight loss supplements. It’s also a thickening agent in many common foods, including ice cream, salad dressings, and yogurt.

How it works: Guar gum is a dietary fiber that expands in your stomach. This promotes a feeling of fullness, thus reducing appetite to help you eat less. It also has laxative properties.

How to take it: Most guar gum supplements are taken orally 2 to 3 times a day with meals. They’re also available in powder forms. Follow the instructions on the label for any product you use.

Effectiveness: Guar gum may support weight loss by improving digestion and reducing appetite. One study found that guar gum reduces hunger more than OTC bran products.

Cost: Guar gum powder costs around $13 for a 16-ounce supply. You can get around 120 capsules in the same price range. Costs vary by brand and store.

Common side effects: The most common side effect of guar gum supplements is gas. If you exceed the recommended dosage, there’s also a chance of choking if the fiber expands in your throat. You should take it with water to reduce this risk. Additionally, allergies and sensitivities to guar gum are common and can cause diarrhea, abdominal cramps, vomiting, and other symptoms, some of which may be severe and/or life-threatening.

Chromium picolinate

Chromium is a mineral that improves your body’s response to insulin, which regulates your blood sugar.

Chromium picolinate is one of several chemical compounds of chromium sold as a nutritional supplement as a potential weight loss aid.

How it works: Chromium picolinate may help regulate blood sugar because of its effect on insulin.

How to take: When using chromium picolinate (or any) supplements, be sure to follow the instructions on the label. It’s an ingredient in many multivitamins, but you can also find it as a daily oral supplement on its own.

Effectiveness: Some trials found that chromium picolinate may support modest weight loss alongside a reduced-calorie diet, especially when paired with physical activity. But in another meta-analysis of studies, no evidence was found to support its use for overweight or obese adults.

Cost: Oral chromium picolinate capsules typically cost around $10 for a 250-count supply. Costs vary by brand and store.

Common side effects: The most common side effects of chromium picolinate include insomnia, headache, and mood changes, such as irritability.

Other OTC diet pills and supplements not included here

Other OTC pills and supplements are not included here because of the lack of evidence of their weight loss benefits. Hoodia and forskolin have some possible benefits, like glucose metabolism improvement in mice from forskolin, but evidence for weight management benefits in humans is lacking.

Keto weight loss pills claim to increase ketone levels in your body, which reportedly help your body break down fat for use as energy. Currently, there’s little evidence to support the claim that these supplements help you lose weight.

What over-the-counter weight loss pills work best?

As of 2024, Alli is the leading over-the-counter weight loss pill. With FDA approval and plenty of research backing its benefits, people trust Alli to help with weight loss without a prescription.

OTC fat burners like PhenQ, also show some promise and may offer a natural alternative to prescription weight loss medications.

Never start any over-the-counter dietary supplement or natural medicine, including Alli, without talking to your healthcare provider first. You want to ask your provider whether weight loss pills are safe during your weight loss consultation. If you struggle to ask your provider about your weight, read up on how to ask your doctor for weight loss pills.

What to know about the safety and side effects of OTC weight loss pills

Weight loss supplements are considered dietary supplements, which are treated as food and aren’t regulated by the FDA.

Although some people are satisfied with the results of using OTC weight loss pills and supplements, these products can cause side effects and may interact with other medications, including prescription drugs.

Little comprehensive research exists on the safety and effectiveness of branded dietary supplements. What research does exist is often limited to ingredients. And the amount of an ingredient in a supplement isn’t monitored and can vary widely.

In general, the side effects of many OTC weight loss pills include nausea, gas, and diarrhea. But more serious side effects and adverse reactions are possible with any medication or supplement. Not every weight loss pill is safe, which is why consulting a licensed healthcare provider is important when considering taking any dietary supplement.

What to do if OTC weight loss pills don’t work for you

OTC weight loss pills won’t provide the same results for everyone. If you’ve tried over-the-counter medications for weight loss without seeing progress, find a licensed healthcare professional on Klarity Health. A professional can help you with your weight loss goals and help you find the right medical weight loss program.

A medically-supervised weight loss plan might include a medication-managed weight loss approach. FDA-approved prescription medications are proven to be generally safe and effective in clinical trials. They may be covered by health insurance too.

The best prescription weight loss medications include:

Zepbound (tirzepatide)
Wegovy (semaglutide)
Saxenda (liraglutide)
Qsymia (phentermine-topiramate)
Contrave (buproprion-naltrexone)
Adipex-P (phentermine)
Xenical (orlistat)

Is weight loss medication right for you? Find a provider and find out.

Find a healthcare provider on Klarity Health and start a tailored weight loss journey today

Through Klarity Health, find a licensed medical provider to help you manage your weight loss. Independent providers on Klarity Health offer in-person and/or telehealth appointments. And you can usually have an appointment in as little as 48 hours. Start your weight loss journey today.

How we reviewed this article: This article went through rigorous fact-checking by a team of medical reviewers. Reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the author. Learn more about the editorial and medical review process and standards for the HelloKlarity site.

*Appointments are generally available within 24 hours. Free initial consultations are available only with select providers. Prescriptions, particularly for controlled substances, may require an in-person evaluation depending on the state of residence and current federal regulations.

The information provided in this article is for educational purposes only and should not be construed as medical advice. Controlled substances may not be appropriate for all patients and any mention of these medications is for educational purposes only, not for marketing or encouraging self-diagnosis. Always seek the guidance of a qualified healthcare professional with any questions or concerns you have regarding your health. Providers on Klarity Health are independent practitioners with clinical autonomy. Nothing in this article is intended to diagnose or treat any condition, including guaranteeing prescription medication of any kind or dosage. Not all providers on Klarity Health prescribe all medications, particularly medications that are controlled substances.

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