When it comes to weight loss, there is no shortage of pills, drinks, and supplements claiming to help the weight fall off. But do weight loss pills help, and are they safe?
The best weight loss pills may contain one or more active ingredients intended to increase fat burning, decrease appetite, or reduce absorption of fat.
Not all weight loss pills and supplements are created equal. Certain pills may cause unpleasant side effects while others may not be proven to result in weight loss.
We will look at the following nine weight loss pills and supplements:
- Alli (orlistat)
- garcinia cambogia extract
- green tea extract
- conjugated linoleic acid
- prescription weight loss pills
Alli is the brand name for the drug orlistat. It is one of the most popular weight loss pills.
Orlistat is available as a prescription drug and also sold over the counter. It works by preventing the body from breaking down of some of the fat that people eat. When the intestines absorb less fat, weight loss may occur.
A review of 11 studies indicated that orlistat might increase weight loss by a small amount. The review found that those who took orlistat lost an average of 2.9 percent more weight than those who did not take the drug.
Orlistat may cause a change in bowel habits. People taking orlistat may experience side effects, such as diarrhea, stomach pain, and difficulty controlling bowel movements.
Caffeine is a stimulant found in coffee, tea, soft drinks, and chocolate. It is also often added to diet pills and supplements.
According to a study of 76 obese adults, people who had high caffeine intake saw a greater reduction in fat mass, weight circumference, and overall weight compared to those who had low caffeine intake.
Side effects of caffeine include jitteriness, increased heart rate, and trouble sleeping.
Glucomannan is a type of fiber supplement. It works by absorbing water in the gut, leading to a feeling of fullness that may prompt people to eat less.
Studies appear to be conflicting on whether glucomannan can aid in weight loss, however.
A 2005 study of 176 people indicated that glucomannan contributed to weight loss in healthy, overweight adults.
However, a more recent review of randomized control trials indicated that glucomannan did not appear to result in significant weight loss.
For those who do take glucomannan, side effects may include gas, diarrhea, and stomach pain.
Garcinia cambogia is a fruit that contains hydroxycitric acid, which is thought to help weight loss.
Garcinia cambogia extract contains the juices from this small fruit and is available as a weight loss pill. Garcinia cambogia may inhibit or prevent a fat-producing enzyme called citric acid lyase.
There is little scientific evidence to support the use of this extract to help with weight loss. According to one report, the effectiveness of the extract in long-term clinical trials and large-scale studies has not been proven.
Although garcinia cambogia extract may not aid in weight loss, it does not appear to cause many side effects when taken in reasonable doses. The report above also indicated that adverse effects did not occur with a dietary dosage of up to 2,800 milligrams (mg) per day.
The body produces pyruvate when it breaks down sugar. Pyruvate is also sold as a supplement to assist with weight loss by helping break down fat and boosting metabolism.
According to the National Institute of Health's Office of Dietary Supplements, pyruvate may have some effects on weight loss. Existing studies are weak, so results are not conclusive.
Side effects of pyruvate include gas and bloating.
Many diet pills contain green tea because it may increase the body's ability to burn fat, and especially fat in the stomach area.
Although more evidence is needed, some research indicates that drinks containing green tea extract may promote the loss of fat around the stomach area. The increase in fat loss may also result in modest weight loss.
Although green tea extract is usually well tolerated, it can cause stomach pain, constipation, and nausea.
Conjugated linoleic acid is a type of fatty acid found mostly in beef and dairy. It has been marketed as one of the best weight loss pills for its potential to boost metabolism and decrease appetite.
However, the majority of the studies on conjugated linoleic acid leading to weight loss have been carried out on animals. According to a review of research, weight loss appears to be minimal in human studies.
Conjugated linoleic acid appears to be safe in doses of up to 6 grams per day for up to 12 months. Possible side effects include stomach discomfort, diarrhea, or constipation. It may not be suitable for people who have diabetes.
Hydroxycut is a popular dietary supplement. There are different Hydroxycut products, which contain various ingredients. Hydroxycut products typically contain plant extracts and caffeine, although caffeine-free versions of the supplement are also available.
There are no studies that review Hydroxycut specifically. Caffeine, which has been studied, may contribute to small amounts of weight loss.
Since the ingredients of Hydroxycut vary, it is difficult to state the possible side effects. Hydroxycut supplements that contain caffeine may cause nervousness and increased heart rate.
Hydroxycut is considered a supplement and does not go through the same rigorous testing as drugs to determine its safety.
Certain weight loss pills are only available through a doctor's prescription. Although there are various pills on the market, most weight loss medications work by making it harder to absorb dietary fat or by suppressing the appetite.
Two common weight loss pills are Belviq and Qsymia.
Prescription pills may lead to some weight loss, but they can have side effects. Depending on the prescription, side effects of weight loss pills can include stomach pain, dry mouth, and diarrhea.
When it comes to the best weight loss pills, it appears there is no magic bullet. Although some of the diet pills and supplements mentioned above may contribute to weight loss, the amounts are usually modest.
Caffeine, green tea extract, and orlistat appear to have the most research to back up their claims.
Some weight loss pills can also lead to side effects, with the most common being stomach discomfort and changes in bowel movements.
Dietary supplements do not face the same scrutiny as drugs that are approved by the United States Food and Drug Administration (FDA), so their safety is not always fully understood. Before taking any supplement for weight loss, it is best to talk with a doctor or other healthcare professional.
The best bet for people trying to lose weight is to reduce portion size, eat lean protein and veggies, and get regular exercise.