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5 Weight Loss Supplements With Scientific Support

5 Weight Loss Supplements With Scientific Support

  • Having trouble losing that stubborn belly fat? Research suggests these supplements might help a lending hand.

The weight loss industry is one where I see businesses shed all decency in pursuit of profit. Dietary supplements for weight loss are the holy grail for shady marketers—unregulated and cheap. That said, I’ve seen enough science to believe some supplements can help support healthy weight loss.

Dietary supplements provide nutritional support and can help address several health conditions. I’ve used them, with mixed results, for several years. I’ve read the science supporting weight loss supplements and my goal in this article is to save you the hassle of doing the same.

Note: Check out the Best Vitamin & Supplement Brands Guide to ensure any product you buy contains safe and potent ingredients.


Weight loss can be a tricky subject to approach. In my opinion, this is largely explained by the uniqueness of each individual. Lifestyle differences, genetic differences, and even geographic differences play a role. I believe weight loss supplements help in a combination of the following three ways:

Metabolic Support: A shift in how nutrients are used in your body.

Nutritional Support: A shift in what nutrients are available for use.

Psychological Support: A shift in perception of mealtimes and/or lack of.

An example of all three of these is illustrated by fasting for weight loss. Fasting provides metabolic support by burning excess glucose stores (fat), caused by lowered external nutritional support (less food), which—at least for me—offers psychological support by being so different from normal eating habits.

Another important note: some supplements, such as raspberry ketones, are popular mostly for their support of dietary changes like the ketogenic diet. Using such supplements without accompanying dietary change isn’t likely to provide nearly the same beneficial outcomes.

different protein powder supplements in spoonsProtein Supplements

One 12-week study found protein supplements, when combined with a reduction in daily caloric intake, helps lose weight(R). This study also observed no changes in physical performance or strength despite the loss of weight. That’s always a concern with calorie-restriction.

Another clinical trial found that protein supplements don’t help maintain weight loss if taken during without calorie restriction (R). In other words, protein supplements may help you lose weight if you cut back your daily calories but they won’t help keep the weight off once you resume normal eating habits.

In two cross-over studies, protein supplements were shown to reduce feelings of hunger and increase feelings of fullness after eating (R). This may not have a direct impact on weight loss but is likely to help combat the mental and emotional difficulties associated with many weight loss programs. It’s nice to not feel like you’re starving yourself when you’re starving yourself.

I consider protein supplements to offer metabolic, nutritional, and psychological support for weight loss.

Note: Protein powder supplements often contain high amounts of Branched-Chain Amino Acids (BCAAs). These compounds will signal mTor and disrupt a fast quickly. Low-BCAA supplements such as Collagen Peptides can help avoid this issue.

garcinia cambogia fruits
Garcinia Cambogia fruit is an excellent natural source of Hydroxycitric acid (HCA)

Hydroxycitric Acid (HCA)

HCA is an extract of the plant Garcinia Cambogia and is probably the most popular weight loss supplement in the world. One well-designed study found HCA significantly lowers body fat concentration regardless of age or gender (R). My only issue with this study is one of the primary authors worked for the company that funded the study.

HCA works by reducing the influence of a certain enzyme in the body. This enzyme, ATP-Citrate-Lysase, can actually stop the body from storing excess fat. Animal testing suggests HCA helps support weight loss both by reducing the amount of fat stored and lowering appetite (R).

Other animal studies suggest supplementation with HCA-containing compounds, such as Garcinia Cambogia, may have unwanted side effects. One study found Garcinina Cambogia increased liver mass, caused oxidative stress, and increased inflammation (R). These researchers still observed significant weight loss.

I consider HCA as offering nutritional and metabolic support for weight loss. Given the research I’ve read, I would consider long-term use to be high-risk for negative side effects.

green coffee beans
Green Coffee Beans (unripe) are an excellent natural source of Chlorogenic Acid (CA)

Chlorogenic Acid

Chlorogenic Acid (CA) is an active ingredient in Hydroxycut—probably the oldest weight loss supplement on the market. Research suggests it may support healthy weight loss, lower blood pressure, lower inflammation, and even promote a positive mood (R).

Chlorogenic Acid works similarly to how statins reduce the production of cholesterol. It lowers the absorption and production of fats while simultaneously increasing the rate they are burned (R).

Coffee beans are a common food source of chlorogenic acid. This helps explain the effectiveness of using green coffee bean extract for weight loss (R). Much of the research I’ve seen—at least on the specific actions of CA—is from animal studies. This doesn’t negate the observations but should certainly be taken with a grain of salt.

Research suggests chlorogenic acid positively influences how the brain produces and utilizes certain neurotransmitters (R)(R)(R). For this reason, I consider CA to offer metabolic and psychological support for weight loss.

Coleus Forskohlii illustration
Coleus Forskohlii (forskolin) increases cAMP and can lower body fat percentage

Forskolin (Coleus forskohlii)

Forskolin, also sold under the Latin name Coleus forskohlii, and is one of the most popular supplements for weight loss on the market. It’s an amazing compound with some gnarly health benefits—but shedding pounds isn’t among them.

Forskolin was first popularized as a weight loss supplement after a study among 23 women found it able to reduce fat gain (R). All things considered, it’s hard to overstate how underwhelming this study was. Researchers concluded as follows:

Results suggest that [Forskolin] does not appear to promote weight loss but may help mitigate weight gain in overweight females with apparently no clinically significant side effects.

Forskolin is used in many clinical settings to increase levels of two notable compounds in the body of humans and animals: adenylyl cyclase (CA) and Cyclic adenosine monophosphate (cAMP) (R).

Another interesting study found that CA levels are significantly lower in the morbidly obese (R). It raises the question of whether compounds like forskolin, able to increase levels of CA, might have some favorable impact here. I’ve not seen any research showing a direct connection.

Where forskolin really shines is as an antiaging supplement. Calorie-restriction has become a popular mechanism for studying antiaging (R)(R). Diets lower in calories, or those with periods of fasting, increase levels of cAMP. To some degree, forskolin supplements mimic the effect of low-calorie diets—but not necessarily the weight loss aspect.

I consider forskolin to offer only metabolic support for weight loss—to only a marginal degree. From personal experience, I would describe forskolin as increasing energy levels but not impacting weight or body fat.

Conjugated Linoleic Acid foods
Conjugated Linoleic Acid (CLA) is found in foods like beef, cheese, milk, and eggs

Conjugated Linoleic Acid (CLA)

Conjugated Linoleic Acid caught the attention of the scientific community in the late 1970s by inhibiting cancer growth in mice (R). Since then, CLA has been the subject of research investigating its support in areas of cardiovascular, immune, and metabolic health (R).

Research in support of Conjugated Linoleic Acid for weight loss is mixed. A small human trial found CLA able to lower body mass index (BMI), total body fat percentage, and overall weight (R).

Science suggests that CLA reduces fat much like Chlorogenic Acid does by reducing the amount of fat metabolized from diet and increasing the rate that existing fat is burned (R). Also much like Chlorogenic acid, this increases inflammation likely making CLA a poor candidate for long-term use.

I have seen several studies observing little to no effect on weight (R)(R)(R). Food sources of CLA include dairy, beef, and butter. Needless to say; the CLA extract of these foods may help weight loss—not eating more of the foods!

Given the evidence of CLA influencing how fats are absorbed from dietary sources, as well as how existing fats are metabolized, I believe that Conjugated Linoleic Acid offers metabolic and nutritional support for weight loss—though that support isn’t well documented. Personally, I’d stay away from this one.


The supplements in this article all have some degree of scientific support for helping lose weight. In most cases, the support is marginal and also accompanied by conflicting results from other studies.

Many studies I’ve read on supplements for weight loss have obvious conflicts of interest. For example, a supplement company financing the study. This doesn’t mean a study is wrong but it’s certainly something to keep in mind.

I don’t believe that taking supplements for weight loss is likely to provide most people with the results they dream of. Protein supplementation combined with calorie restriction has strong scientific support. Personally, I like this option because it’s little more than a dietary change.

If I had to pick another supplement, Hydroxycitric Acid from sources like Garcinia Cambogia would be my choice for short-term assistance with weight loss. Forskolin would be my choice for helping decrease body-fat and for helping to maintain energy levels during calorie-restricted periods.

I caution anyone considering any supplements for weight loss to speak with their doctor to make sure it’s not going to interfere with medications or existing health conditions. Having a complete awareness of such risk factors is essential in achieving weight loss goals.