Countless supplements on the market claim to offer a quick way to lose excess weight.
Appetite suppressants are types of supplements that work by reducing appetite, thereby decreasing food intake and promoting weight loss .
While certain types of appetite suppressants can only be prescribed by a doctor, many are available without a prescription.
Here’s a review of 12 over-the-counter appetite suppressants, their effectiveness, and safety
1. Conjugated Linoleic Acid (CLA)
Conjugated linoleic acid (CLA) is a type of polyunsaturated fatty acid found naturally in foods like dairy and beef. It is also sold in concentrated form as a weight loss supplement.
How it works : CLA has been shown to affect genes and hormones that regulate appetite. It can also increase the number of calories burned at rest, increase lean body mass, and stimulate fat loss.
Efficacy : While CLA reduces appetite and intake in animal studies, it has not been shown to reduce appetite in humans.
A 12-week study in 62 people showed that 3.9 grams of CLA per day had no effect on appetite, body composition, or the number of calories burned.
Although CLA supplements have been shown to promote fat loss in some studies, their impact on weight loss is small.
For example, a review of 15 studies found that overweight people who supplemented with CLA for at least six months only lost an average of 1.5 pounds (0.7 kg) more than people in the control group.
Side Effects : Taking CLA can cause unpleasant side effects, such as diarrhea and gas. Long-term supplementation can even cause serious complications, such as liver damage and increased inflammation.
CLA is a branded dietary supplement as an appetite suppressant. However, human studies have shown that CLA has little impact on appetite and weight loss.
2. Bitter Orange (Synephrine)
Bitter orange is a type of orange that contains synephrine, a compound that can be effective in reducing appetite.
Synephrine is structurally similar to the popularly popular ephedrine, a weight loss drug, which has been banned from use in dietary supplements since 2004 due to serious side effects.
Bitter orange supplements are marketed to promote weight loss by reducing appetite and are available without a prescription.
How It Works : Bitter orange is believed to stimulate weight loss by increasing your basal metabolic rate, or calories burned at rest, thereby stimulating the breakdown of fat and suppressing your appetite.
Efficacy : Although research has shown that synephrine increases the number of calories burned, its effect on weight loss is inconclusive.
Because bitter orange is often combined with other compounds, such as caffeine, in weight loss supplements, its effectiveness is difficult to interpret.
A review of 23 studies found that 20 to 35 mg of synephrine per day increased metabolic rate and had a moderate impact on weight loss.
However, some of the studies did not produce weight loss or even weight gain after treatment with synephrine.
Side Effects : Reported side effects of synephrine include:
- Incrise of cardiac frecuency.
- High blood pressure
However, it is not yet known whether synephrine alone or in combination with other stimulants causes these symptoms.
Bitter orange contains a compound called synephrine that can boost metabolism and stimulate weight loss. However, research shows mixed results.
3. Garcinia Cambogia
Garcinia Cambogia diet pills are one of the most popular weight loss supplements on the market.
Made with an extract derived from the rind of the Garcinia gummi-gutta fruit, garcinia cambogia pills are used to suppress appetite and promote weight loss.
How it works: Garcinia cambogia extract contains hydroxycitric acid (HCA), which can reduce appetite by increasing serotonin levels in the brain and reducing carbohydrate metabolism.
Efficacy : A review of 12 studies found that participants who supplemented with garcinia cambogia containing 1,000–2,800 mg of HCA per day for 2–12 weeks lost an average of 1.94 pounds (0.88 kg) more than those who took placebo pills.
Another study in 28 people showed that garcinia cambogia was more effective in reducing appetite, increasing fullness, and decreasing hunger than a placebo.
However, other studies have shown that garcinia cambogia has little to no effect on appetite or weight loss.
Side Effects : Although it is generally considered safe, consuming garcinia cambogia can cause side effects in some people, such as:
- Hepatic failure in extreme cases.
Some research shows that garcinia cambogia suppresses appetite and promotes weight loss.
Glucomannan is a type of soluble fiber derived from the edible roots of the konjac plant.
Because it can absorb up to 50 times its weight in water, it is used as a weight loss supplement to increase fullness and reduce appetite.
How It Works: Glucomannan is understood to stimulate weight loss by reducing appetite, increasing feelings of fullness, slowing down digestion, and blocking the absorption of fat and protein.
Efficacy : Studies on the impact of glucomannan on weight loss have provided inconsistent results.
A review of six studies found that 1.24–3.99 grams of glucomannan per day for up to 12 weeks resulted in short-term weight loss of up to 6.6 pounds (3 kg).
However, the researchers concluded that the results were not statistically significant and that larger, longer-term studies are needed.
Side Effects: Glucomannan can cause side effects such as:
- Constipation .
- Abdominal discomfort
Glucomannan is a type of soluble fiber that can promote short-term weight loss. However, the results of the studies are not conclusive.
5. Hoodia Gordonii
Hoodia gordonii is a type of succulent plant traditionally used by the indigenous peoples of southern Africa as an appetite suppressant.
Hoodia gordonii extracts are used in dietary supplements that claim to reduce appetite and enhance weight loss.
How it works: Although the mechanism by which Hoodia gordonii suppresses hunger is unknown, some scientists link it to a compound called P57, or glycoside, which can affect the central nervous system and decrease appetite.
Efficacy : There is little evidence to support the use of Hoodia gordonii to promote weight loss, and few human studies have examined the plant.
A 15-day study in 49 overweight women found that 2.2 grams of Hoodia gordonii per day, one hour before meals, had no effect on body weight or calorie intake compared to a placebo.
Side effects: Hoodia gordonii can cause:
- Increased heart rate
- High blood pressure.
- Liver failure.
Currently, there is no evidence to support the use of Hoodia gordonii to lose weight or reduce appetite.
6. Green coffee bean extract
Green coffee extract is a substance derived from the raw seeds of the coffee plant and is popularly used as a weight loss supplement.
How it works: Green coffee beans contain high levels of chlorogenic acid, which can inhibit the accumulation of fat. The extract also contains caffeine, which decreases your appetite.
Efficacy : A recent study in people with metabolic syndrome showed that people taking 400 mg of green coffee extract per day experienced a significant decrease in waist circumference and appetite compared to a placebo group.
An analysis of three studies found that overweight participants who took 180 or 200 mg per day of green coffee extract for up to 12 weeks experienced an average weight loss of 6 pounds (2.47 kg) more than those who took placebos.
Side Effects: Although green coffee bean extract is generally well tolerated, it can cause headaches and an increased heart rate in some people.
Several research studies have shown that green coffee extract can reduce appetite and promote weight loss.
The guarana plant has been used for hundreds of years for various purposes, including appetite suppression.
How it works: guarana contains more caffeine than any other plant in the world. Caffeine stimulates the nervous system and has been shown to decrease appetite and increase metabolism.
Efficacy: There is insufficient evidence to support the use of guarana to suppress appetite and promote weight loss.
However, test tube and animal studies show that guarana extract can stimulate metabolism and limit fat cell production by suppressing certain genes.
Side Effects: Because guarana is high in caffeine, it can cause insomnia, headaches, nervousness, and increased heart rate and anxiety, especially when taken in high doses.
Guarana, which is especially high in caffeine, can increase metabolism, but more research is needed to determine whether it suppresses appetite or promotes weight loss.
8. Acacia fiber
Acacia fiber, also known as gum arabic, is a type of indigestible fiber promoted as a means of suppressing appetite and promoting fullness.
How it works: Acacia fiber slows digestion, suppresses appetite, increases fullness, and inhibits glucose absorption from the gut, which can help with weight management.
Efficacy: A six-week study of 120 women found that those taking 30 grams of acacia fiber per day lost significantly more body fat than those taking a placebo.
Similarly, a study in 92 people with diabetes showed that 30 grams of acacia fiber per day for three months significantly reduced abdominal fat.
Side Effects – Potential side effects of consuming acacia fiber include:
Acacia fiber can stimulate weight loss by increasing feelings of fullness and suppressing appetite.
9. Saffron extract
Saffron extract is a substance derived from the stigma, or the female part of the flowers where pollen is collected, of the saffron flower.
How it works: Saffron extract is believed to contain several substances that can increase feelings of fullness by stimulating mood.
Efficacy: A study in 60 overweight women showed that those who took 176 mg of saffron extract per day experienced a significant reduction in snack and lost more weight than women on a placebo pill.
While these results are promising, larger and longer-term studies must be conducted to understand saffron’s role in appetite reduction and weight loss.
Side Effects : Saffron extract is generally well tolerated, but it can cause dizziness, fatigue, dry mouth, anxiety, nausea, and headache in some people.
Some evidence supports the use of saffron extract as a way to reduce hunger and lose weight.
10. Guar gum
Guar gum is a type of fiber derived from the Indian bean, or Cyamopsis tetragonoloba.
How it works: Guar gum acts as a bulking agent in your gut. Suppresses appetite by slowing digestion and increasing feelings of fullness.
Efficacy: One study found that consuming 2 grams of guar gum per day resulted in significant reductions in hunger and a decrease in snacking between meals by 20%.
Other studies show similar results, indicating that guar gum may be effective in reducing cravings and total calorie intake.
However, guar gum has not been proven as an effective weight loss tool.
Side Effects: Guar gum can cause adverse side effects, such as:
- Abdominal discomfort
- Abdominal distension.
Guar gum is a type of fiber that can be effective in reducing snacking between meals and lowering overall calorie intake.
11. El forskolin
Forskolin is a compound extracted from the Coleus forskohlii plant.
How it works: Forskolin claims to help you lose weight by reducing your appetite, improving metabolism, and increasing the breakdown of fat in your body.
Efficacy : Human studies investigating the effect of forskolin on weight loss and appetite suppression in humans are limited.
However, several studies show that doses of up to 500 mg of forskolin per day failed to reduce appetite, decrease food intake, or stimulate weight loss in overweight people.
Side Effects: Little is known about the potential side effects of Coleus forskohlii, although one study reported diarrhea and increased bowel movements.
Forskolin appears to have little impact on appetite or weight loss. However, research on this supplement is ongoing.
12. Chromium picolinate
Chromium is a mineral commonly used for controlling blood sugar, reducing hunger, and decreasing cravings.
How it works: Chromium picolinate is a highly absorbable form of chromium that helps reduce appetite and cravings by affecting neurotransmitters involved in regulating mood and eating behavior.
Efficacy: A review of 11 studies in 866 overweight or obese people found that daily supplementation with 137–1,000 mcg of chromium for 8–26 weeks led to reductions in body weight of 1.1 pounds (0.5 kg) and body fat of 0.46 %.
Side Effects: Potential side effects related to Chromium Picolinate include:
Some research has shown that chromium picolinate can be effective in reducing appetite and promoting weight loss.
The bottom line
- Many supplements on the market claim to suppress your appetite and increase weight loss. However, very few of the dietary supplements listed above have sufficient evidence to suggest effectiveness in reducing appetite.
- While certain supplements, such as acacia fiber, guar gum, and chromium picolinate, have been shown to decrease appetite, they can cause adverse side effects, such as headaches, diarrhea, and abdominal discomfort.
- There are many more effective and evidence-based ways to control appetite, cut back on snacking, and lose weight without relying on dietary supplements.
- Cutting back on processed foods, reducing your total calorie intake, and increasing activity levels are tried and true methods that will put you on the path to weight loss.