Are there any natural supplements that you can take for weight loss with a normal diet?
12 Popular Weight Loss Pills and Supplements Reviewed
There are many different weight loss solutions out there.
This includes all sorts of pills, drugs and natural supplements.
These are claimed to help you lose weight, or at least make it easier to lose weight combined with other methods.
They tend to work via one or more of these mechanisms:
Reduce appetite, making you feel more full so that you eat fewer calories.
Reduce absorption of nutrients like fat, making you take in fewer calories.
Increase fat burning, making you burn more calories.
Here are the 12 most popular weight loss pills and supplements, reviewed by science.
1. Garcinia Cambogia Extract
Garcinia cambogia became popular worldwide after being featured on the Dr. Oz show in 2012.
It is a small, green fruit, shaped like a pumpkin.
The skin of the fruit contains hydroxycitric acid (HCA). This is the active ingredient in garcinia cambogia extract, which is marketed as a diet pill.
How it works: Animal studies show that it can inhibit a fat-producing enzyme in the body and increase levels of serotonin, potentially helping to reduce cravings (1, 2).
Effectiveness: One study with 130 people compared garcinia against a dummy pill. There was no difference in weight or body fat percentage between groups (3).
A 2011 review that looked at 12 studies on garcinia cambogia found that, on average, it caused weight loss of about 2 pounds (0.88 kg) over several weeks (4).
Side effects: There are no reports of serious side effects, but some reports of mild digestive problems.
Even though garcinia cambogia may cause modest weight loss, the effects are so small that they probably won't even be noticeable.
Hydroxycut has been around for more than a decade, and is currently one of the most popular weight loss supplements in the world.
There are several different types, but the most common one is simply called "Hydroxycut."
How it works: It contains several ingredients that are claimed to help with weight loss, including caffeine and a few plant extracts.
Effectiveness: One study showed that it caused 21 lbs (9.5 kg) of weight loss over a 3 month period (5).
Side effects: If you are caffeine sensitive, you may experience anxiety, jitteriness, tremors, nausea, diarrhea and irritability.
Unfortunately, there is only one study on this supplement and no data on long-term effectiveness. More research is needed.
Caffeine is the most commonly consumed psychoactive substance in the world (6).
It is found naturally in coffee, green tea and dark chocolate, and added to many processed foods and beverages.
Caffeine is a well known metabolism booster, and is often added to commercial weight loss supplements.
How it works: Short-term studies have shown that caffeine can boost metabolism by 3-11%, and increase fat burning by up to 29% (7, 8, 9, 10).
Effectiveness: There are also some studies showing that caffeine can cause modest weight loss in humans (11, 12).
Side effects: In some people, high amounts of caffeine can cause anxiety, insomnia, jitteriness, irritability, nausea, diarrhea and other symptoms. Caffeine is also addictive and can reduce the quality of your sleep.
There really is no need to take a supplement or a pill with caffeine in it. The best sources are quality coffee and green tea, which also have antioxidants and other health benefits.
Caffeine can boost metabolism and enhance fat burning in the short term. However, a tolerance to the effects may develop quickly.
4. Orlistat (Alli)
Orlistat is a pharmaceutical drug, sold over-the-counter under the name Alli, and under prescription as Xenical.
How it works: This weight loss pill works by inhibiting the breakdown of fat in the gut, making you take in fewer calories from fat.
Effectiveness: According to a big review of 11 studies, orlistat can increase weight loss by 6 pounds (2.7 kg) compared to a dummy pill (13).
Other benefits: Orlistat has been shown to reduce blood pressure slightly, and reduced the risk of developing type 2 diabetes by 37% in one study (14, 15).
Side effects: This drug has many digestive side effects, including loose, oily stools, flatulence, frequent bowel movements that are hard to control, and others. It may also contribute to deficiency in fat-soluble vitamins, such as vitamins A, D, E and K.
It is usually recommended to follow a low-fat diet while taking orlistat, in order to minimize side effects.
Interestingly, a low carb diet (without drugs) has been shown to be as effective as both orlistat and a low-fat diet combined (16).
Orlistat, also known as Alli or Xenical, can reduce the amount of fat you absorb from the diet and help you lose weight. It has many side effects, some of which are highly unpleasant.
5. Raspberry Ketones
Raspberry ketone is a substance found in raspberries, which is responsible for their distinct smell.
A synthetic version of raspberry ketones is sold as a weight loss supplement.
How it works: In isolated fat cells from rats, raspberry ketones increase breakdown of fat and increase levels of a hormone called adiponectin, believed to be related to weight loss (17).
Effectiveness: There is not a single study on raspberry ketones in humans, but one rat study using massive doses showed that they reduced weight gain (18).
Side effects: They may cause your burps to smell like raspberries.
There is no evidence that raspberry ketones cause weight loss in humans, and the rat studies showing it to work used massive doses.
6. Green Coffee Bean Extract
Green coffee beans are simply normal coffee beans that haven't been roasted.
They contain two substances believed to help with weight loss, caffeine and chlorogenic acid.
How it works: Caffeine can increase fat burning, and chlorogenic acid can slow the breakdown of carbohydrates in the gut.
Effectiveness: Several human studies have shown that green coffee bean extract can help people lose weight (19, 20).
A review of 3 studies found that the supplement made people lose 5.4 more pounds (2.5 kg) than placebo, a dummy pill (21).
Other benefits: Green coffee bean extract may help lower blood sugar levels, and reduce blood pressure. It is also high in antioxidants (22, 23, 24, 25).
Side effects: It can cause the same side effects as caffeine. The chlorogenic acid in it may also cause diarrhea, and some people may be allergic to green coffee beans (26).