Key takeaways:
Eating behavior is complicated and can be affected by factors other than hunger.
There is no reliable evidence to suggest that natural appetite suppressant supplements work.
Natural diet supplements are not FDA-regulated and can contain harmful substances.
People interested in achieving a healthy weight may look to natural, over-the-counter (OTC) remedies that claim to control cravings and hunger. “All natural” products might sound like a tempting, low-risk option for folks interested in being fit and healthy.
In reality, there’s more to eating than just being hungry. Also, some supplements on the market may interfere with medications or cause unwanted side effects. Here, we’ll take a look at some products that claim to suppress appetite and what we know about them.
How can I suppress my appetite?
There are many different ways that our bodies work to match hunger with food intake. At the most basic level, our stomach and intestines send messages through nerves and hormone signals to our brains, which cause us to feel hunger and eat. When we eat and start to digest, other hormones signal to our brain that our energy needs have been met, and that we can stop eating.
For most people, the relationship between our brain and our gut is much more complex. Emotions, habits, and culture can all affect the way we respond to food and behave around it. We sometimes eat for entertainment, pleasure, or as part of a social gathering ritual. We might eat out of boredom or to self-soothe after a stressful day. All this means that our minds and bodies can misread our bodies’ physical cues and struggle to tell the difference between hunger and cravings.
On top of that, our genetic make-up means that some of us will be more prone to overeating and less able to regulate appetite.
The good news is that there are some steps you can take to feel less hungry:
Prioritize calories from lean protein, slow-release carbohydrates, and high-fiber foods.
Cut back on sugar and salt.
Drink more water before and during meals.
Eat slowly and preferably at the same times every day if you can.
Practice mindful eating.
There are also medications that can help to suppress the hunger your brain feels, like Contrave and phentermine. They are not risk-free, but in some cases they can help with weight loss.
Are there any natural alternatives to appetite suppressant prescription drugs like phentermine?
Yes, there are supplements that claim to be natural alternatives to prescription weight-loss medication. You might have heard of some of these, like fenugreek, green tea, and yerba mate. Other examples include:
Glucomannan
Caralluma fimbriata
Griffonia simplicifolia
Garcinia cambogia
At best, these may help you lose a pound or two in the short term. At worst, they could actually cause you harm.
The only true healthy alternatives to prescription weight-loss medications are lifestyle changes. With the right professional support, you can lose more weight through structured behavioral change programs than through usual care alone. The U.S. Preventive Services Task Force (USPSTF) recommends that intensive lifestyle coaching be offered to all adults with obesity.
Do natural appetite suppressants work?
Herbs and supplements do not help people lose weight and keep the weight off long-term. Here, we’ll compare the claims of some popular supplements to the evidence — or lack of it. We’ll also outline any potential risks of natural appetite suppressants.
You can find a more complete list of weight-loss supplements and their evidence and risks in this helpful fact sheet from the National Institutes of Health Office of Dietary Supplements.
Supplements that don’t work for weight loss
Green tea extract
What it is: Green tea extract is a concentrated form of green tea in a capsule.
The claim: Naturally occurring catechins and caffeine are said to speed up metabolism and help with weight loss and weight-loss maintenance.
The evidence: A Cochrane review of 15 randomized control studies found that the effect of green tea extract on weight loss and weight-loss maintenance was so small that it was insignificant.
The risk: Caffeine increases blood pressure and should be used carefully by people with a risk of heart or blood pressure problems.
Conjugated linoleic acid (CLA)
What it is: CLA is a type of fat found in dairy foods and beef. CLA supplements are made by chemically changing natural sources of linoleic acid.
The claim: CLA is said to increase the breakdown of body fat and reduce the amount of fat cells created in the body.
The evidence: While some individual studies may show small improvements in weight compared to a placebo (sugar pill), there is no evidence to support this.
The risk: There isn’t enough good-quality evidence to say if CLA is safe or not. People taking CLA supplements reported upset stomach and change in their bowel habits. There’s also some concern that CLA supplements could affect cholesterol and glucose levels in the blood.
Chitosan
What it is: Chitosan is a supplement made from shells of crustaceans, like shrimp, crabs, and lobster.
The claim: Chitosan is said to bind fats in the gut, reducing their absorption. It is also thought to lower blood cholesterol levels.
The evidence: A Cochrane review of 13 studies concluded that chitosan was linked to a small amount of initial weight loss (3 lb to 4 lb). But when the researchers looked at higher-quality studies over longer periods of time, the effect of chitosan on weight loss was minimal. They noted that the quality of these studies was poor.
The risk: Side effects of chitosan are usually not severe. People report digestive disturbances, such as gas, bloating, nausea, constipation, and heartburn. If you are allergic to shellfish, then it’s best to avoid using this as an appetite suppressant.
Grapefruit
What it is: Grapefruit is a citrus fruit that has been a regular on the fad diet scene for decades.
The claim: Grapefruit and grapefruit essential oil are said to burn fat and boost metabolism.
The evidence: An analysis of the available research in humans found no evidence that grapefruit alone has any effect on weight.
The risk: Grapefruit itself is safe, but it can interact with several common medications, such as blood pressure drugs, blood thinners, erectile dysfunction medications, antihistamines, pain medications, and even birth control pills. It’s best to check with a healthcare provider or pharmacist if you plan to start consuming a lot of grapefruit.
Natural appetite suppressants that could be dangerous
Garcinia cambogia
What it is: Garcinia cambogia is a pumpkin-sized fruit native to Indonesia. It is also known as gamboge, brindleberry, and Malabar tamarind. The main active ingredient is hydroxycitric acid, which is also found in other Garcinia species. Until 2009, it was found in a weight loss pill called Hydroxycut.
The claim: Hydroxycitric acid is said to promote weight loss by increasing metabolism and suppressing appetite.
The evidence: A review of studies found that — at best — a very small amount of short-term weight loss could occur. The researchers commented on the fact that the quality of evidence they reviewed was generally poor and short in duration.
The risk: You can get severe liver failure causing death from using this supplement. Hydroxycut with Garcinia was banned by the FDA in 2009.
Guar gum
What it is: Guar gum is a fiber extracted from the seeds of the guar bean, or cluster bean. It is used in gluten-free foods as a binding agent and in weight-loss supplements.
The claim: Guar gum is said to bind food in the stomach, promoting a feeling of fullness and reducing appetite.
The evidence: In a study of 20 of the best kinds of studies available (randomized, double-blind, placebo-controlled clinical trials), guar gum caused no more weight loss than a placebo pill. More recently, a study showed that guar gum improved waist circumference in people with diabetes, but without lowering weight.
The risk: Guar gum causes more problems than it solves. Abdominal pain, cramps, flatulence, nausea, and diarrhea are common side effects. In the past, there have also been reports of esophageal and intestinal blockage in people taking a now-discontinued version of guar gum.
Glucomannan
What it is: Glucomannan is a fiber that comes from konjac root and is capable of absorbing large amounts of water.
The claim: Similar to guar gum, glucomannan is said to increase feelings of fullness.
The evidence: This review of studies and this analysis did not find evidence suggesting a major impact on weight or body mass index (BMI) from the use of glucomannan. As with other studies looking at natural appetite suppressants, researchers cited both poor quality of studies and too small a sample size (numbers of participants).
The risk: Side effects are mostly related to gastrointestinal discomfort — gas, bloating, diarrhea, and constipation. But in its tablet form, glucomannan was linked to blockage of the esophagus in previous reports.
Ma huang
What it is: Ma huang is a plant native to China, also known as ephedra. The plant’s stem contains plant-based substances called ephedrines, which are similar to the human hormones epinephrine and norepinephrine. Ephedra was commonly combined with caffeine in weight-loss and athletic supplements in the 1990s.
The claim: The active ingredient ephedrine is a stimulant that causes weight loss by increasing energy output and reducing appetite.
The evidence: Ephedrine was found to be somewhat effective for short-term weight loss. People taking it lost 1 lb to 2 lb more than those taking a placebo. But it had no effect on athletic performance.
The risk: Side effects include nausea, vomiting, anxiety, mood changes, high blood pressure, racing heart rate, stroke, seizures, heart attack, and death. The FDA banned ephedra and other plant-based ephedrines in 2004 due to serious safety concerns.
Bitter orange
What it is: Bitter orange refers to a citrus tree and its fruit, also known as Seville orange. The fruit peel, flower, and leaves are used as flavorings and ingredients in many foods, including marmalade and the citrus-flavored liqueur, Triple sec. After the FDA banned ephedra, bitter orange became known as an “ephedra substitute.”
The claim: The active ingredient is synephrine, similar to ephedra (ma huang). Synephrine is claimed to help with weight loss by speeding up metabolism, burning fat, and suppressing appetite.
The evidence: Based on the available evidence , it’s impossible to say whether bitter orange works for weight loss because it is almost always combined with other ingredients. There is some evidence across 23 small human trials that it might boost metabolism. Overall, the evidence is weak or inconclusive.
The risk: People taking bitter orange have experienced a whole range of severe side effects from muscle aches, headaches, and anxiety, to chest pain, dangerously high heart rate, and near-fatal cardiac rhythm problems, strokes, heart attacks, and even death. It’s not clear if these are caused by synephrine alone, or by other ingredients commonly combined with bitter orange in diet supplements.
Supplements without enough evidence that they work or are safe
Chromium
Gambisan
Cynanchum auriculatum
Supplements not tested on humans for weight loss
Fenugreek has only been tested on mice for weight loss and does not work.
Gymnema’s effect on weight has also only been studied in rats.
Hoodia gordonii is thought to suppress appetite in rats, but the only study in humans did not show an effect on weight.
Natural appetite supplements that might work
According to this review, only two supplements might actually suppress appetite in humans:
Caralluma fimbriata, which is an edible cactus and generally thought to be safe
A combination of Garcinia cambogia plus Gymnema sylvestre (see above) — The review states that more research is needed to understand any possible long-term effects.
Are natural appetite suppressants safer than prescription weight loss drugs?
No, natural products are not safer than prescription treatments. Don’t be fooled by the term “natural.” Supplements may be marketed as containing naturally occurring substances, but this does not mean they are harmless.
The problem for the average consumer is that weight-loss supplements are not approved — or even reviewed — by any regulatory body. Because they are not classified as drugs, the FDA doesn’t monitor their safety. The FDA does, however, look into reports of harms caused by them. In fact, the FDA has found that many appetite suppressants claiming to have weight loss benefits have been tainted with other prescription drugs. These include antidepressants, amphetamines, and diuretics.
When considering any supplement, it’s important to weigh its benefits against its risks. Taking a weight-loss supplement is a big health risk for something that is unlikely to have any positive impact on your weight-loss journey.
What are the possible side effects of natural appetite suppressants?
There are many possible side effects, and they vary by type of suppressant. Common ones include:
Gastrointestinal problems (gas, changes in bowel habits, nausea)
Headache
Dizziness
Effects on blood pressure and heart rate
Do I need to talk to a doctor before starting on natural supplements?
Yes, you should always speak with a healthcare provider before you start taking natural supplements. This is especially true if you have other medical conditions or take medications regularly. There are accredited healthcare practitioners who may have experience using supplements as part of a comprehensive weight-loss plan. The key here is that these should be part of a bigger treatment plan under the supervision of an expert.
The bottom line
Many people would be happy to hear about safe, natural supplements that help with weight loss. But the reality is that most supplements have little evidence at best. In fact, they may actually cause more harm than good. It’s best to use supplements — including natural appetite suppressants — when guided by a healthcare provider who has experience with them. In most cases, weight-loss supplements are probably not worth the health risk or the cost.
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