Home VITAMINS, MINERALS & SUPPLEMENTS The Skinny on Weight Loss Supplements: An Assessment of Active Ingredients

The Skinny on Weight Loss Supplements: An Assessment of Active Ingredients

Whether part of a pre-packaged supplement formulation or taken individually, these ingredients can facilitate weight loss. We review each one, its mechanism of action, and its actual effectiveness.

by Douglas Elliot
Weight Loss Supplements

Table of Contents

Americans are obsessive about weight loss, and understandably so. Nearly 40% of American adults aged 20 and over are obese. 71.6% of adults aged 20 and over are overweight, including obesity. (National Health and Nutrition Examination Survey, 2017-2018; Harvard School of Public Health, 2020). And being overweight or obese can all too often lead to further health problems that can destroy the quality of life, and may even lead to premature death. Aside from reasons of health, vanity has the bulk of the U.S. population motivated to lose weight, through a wide variety of different approaches, ranging from supplements to surgery.  [This article, “The Skinny on Weight Loss Supplements: An Assessment of Active Ingredients” was originally published in HealthXWire]

The current market for weight loss supplements is estimated at $45.6 billion, and is anticipated to increase at a compound annual growth rate of more than 16.6%. Supplementation (taking over-the-counter, non-prescription formulations or individual ingredients) is being employed by the domestic population either as an adjunct to making better dietary choices and engaging in cardiovascular or resistance exercise, or as a substitute for taking these more challenging measures. In either case, more than 69.7% of American adults have taken weight loss supplements at some point in their lives.

The challenge: Getting basic information about weight loss

The majority of people taking weight loss supplements choose multiple-ingredient formulations, while those in the remaining minority who do more extensive research tend to seek out individual ingredients, opting instead to create their own weight loss supplement stacks. Those in the latter school tend to do more online research into the effects and dosing of supplements than their multi-ingredient counterparts.

Unfortunately, there is very little in the way of dependable, scientifically-verified data about the efficacy of any of the over-the-counter supplements (single-ingredient and multiple-ingredient formulations) for several reasons.

First, and most significantly, the FDA does not regulate supplement manufacturers and sellers in the way that it regulates and collects data regarding prescription medicines, so publicly-available government information regarding supplements is very sparse. While there are a few exceptions to the foregoing (for example, the government’s banning of products containing ephedra some years back due to its potentially deadly side effects), the government does not provide us with either insight or guidance in terms of either the effectiveness or safety of weight loss supplements.

Second, since supplements are, generally speaking, not patentable, they have not garnered the serious attentions or affections of the major pharmaceutical firms, which are spending their vast reserves of money on researching, developing and testing drugs that will be patented and sold at a significant margin of profit. Clinical trials and their corresponding results are not usually available for non-prescription formulations. Most of the information that is available to consumers regarding supplements (in terms of effectiveness, dosing and side effects) is either anecdotal, or is provided through advertising by the companies marketing them.

One of the challenges to obtaining meaningful data about weight loss supplements is that most individuals using them are doing so in conjunction with some program of dieting or exercise; this makes it virtually impossible to completely isolate the effects actually attributable to the taking of supplements. Laboratory-type controls are non-existent in the supplement world, where there is a great deal of misinformation, sensationalism, and individual trial and error.

An evaluation of ingredients

Having issued a blanket disclaimer in the preceding section, and with the pre-emptive admonition that you should always consult with your healthcare practitioner prior to taking any weight loss supplement (as these may be dangerous given certain medical conditions, or that they may interact with prescription medications that you may be taking), following is an evaluation of some popular ingredients in weight loss supplements that you may find interesting and helpful. The basic mechanisms by which they work vary from ingredient to ingredient, but include metabolic acceleration (increasing the rate of caloric burn by the body at rest), fat absorption and elimination, sugar/insulin modulation and appetite suppression, to name the four major means.


Chromium is an essential trace mineral that can improve insulin sensitivity and enhance protein, carbohydrate, and lipid metabolism. It is categorically regarded as a very gentle appetite suppressant and a minor metabolic stimulant. In addition to its effects on glucose, insulin, and lipid metabolism, chromium has been reported to decrease the percentage of body fat and increase the percentage of lean muscle mass, which may aid in weight loss. Chromium, in doses of more than 50 micrograms daily, can reduce sugar cravings, which can, in turn, suppress appetite. Some research suggests that 1,000 micrograms a day should be considered the upper limit for supplemental chromium intake, because greater doses may cause irregular heartbeat, kidney and liver damage, and increased insulin resistance, but very few incidents of these issues have been reported, and chromium is generally regarded as a very safe supplement. If you are taking insulin or metformin, or if you have pre-diabetes, only take chromium under a doctor’s supervision. Chromium may also interact with medications such as antacids, acid reflux drugs, corticosteroids, beta-blockers, insulin, thyroid drugs and NSAID painkillers. These interactions may cause the chromium to be poorly absorbed by the body or may serve to increase the effects of the other medication to an undesirable degree. Interactions with prescription drugs aside, chromium is well tolerated even in large doses, and chromium picolinate is thought to be the best way to take this supplement due to its superior bioavailability. 


Cinnamon, especially Ceylon cinnamon, aids in metabolism of sugar, and in this respect does something similar to what chromium does, albeit through a different mechanism. Unlike chromium, cinnamon has actually been shown to reduce the amount of glucose entering the bloodstream after a meal. Its active ingredient is cinnamaldehyde, which is also responsible for its characteristic fragrance, taste and “bite.” Cinnamaldehyde also has been shown to increase insulin sensitivity, so it may serve as a mild appetite suppressant. Doses of up to as much as 6,000 milligrams daily have been shown to be beneficial and relatively free of side effects and interactions with most prescription drugs. In the world of supplements, cinnamon is, relatively speaking, very inexpensive and proven to be effective. Cinnamon is often paired with chromium as part of an anti-diabetic (preventive) weight loss stack. Ceylon cinnamon is preferred over the cassia variety, which contains a higher concentration of coumarin, which, in certain quantities, can be toxic to the liver, so be certain to seek out the Ceylon variety. The capsule form of cinnamon is best (you can get a high-quality, low-cost Ceylon cinnamon supplement from Vitacost), as ingesting cinnamon powder can cause irritation of the tongue, gums, throat and sinuses. This might be a good weight loss supplement to try. 


Chitosan, which is sold over-the-counter as a “fat trapper” or a “fat blocker,” is obtained from the shells of shellfish, so if you have any type of seafood allergy or sensitivity don’t even think about taking this supplement. Despite claims made by marketers of chitosan, there is little evidence, either scientific or anecdotal, that it is efficacious. Chitosan, even in relatively small amounts, can cause constipation and stomach upset. This supplement, at least from the standpoint of weight loss, has little going for it.

Green Tea Extract

Green tea extract contains concentrations of epigallocatechin gallate (EGCG), which stimulates the metabolism through thermogenesis, which, in turn, causes your body to burn more calories, even at rest, than it would otherwise do. Paired with the caffeine that is ordinarily present in green tea, there is some evidence to support at least a modest weight loss effect through supplementation with green tea extract. The recommended optimal dose ranges from 400 to 500 milligrams daily. Consuming more than twice this amount daily over time can cause some liver toxicity, so don’t go overboard with this supplement. Also, if you consume more than 200 milligrams of caffeine daily, it may inhibit the effectiveness of this supplement because your body builds up too much of a tolerance to the caffeine in the green tea extract. Vitacost sells a high-quality standardized green tea extract at a very reasonable price in a 250 milligram capsule. If you are particularly sensitive to caffeine, you might wish to try the decaffeinated variety of green tea extract, which is also available from Vitacost. Generally speaking, this is likely a safe weight loss supplement to try.

Green Coffee Extract

Green coffee extract, which comes from the the dried and unroasted coffee fruit – while most of us regard coffee as a bean, it is actually a fruit – has been shown to be somewhat effective in limited trials on obese and overweight individuals. This effect is most likely due to the presence of chlorogenic acid (GCA) in raw coffee. Chlorogenic acid is a polyphenol compound which reduces fat absorption in the gut and may also slightly reduce sugar levels in the bloodstream. The slight thermogenic effect of the GCA is probably enhanced by the caffeine ordinarily present in green coffee; caffeine is a central nervous system stimulant and a slight metabolic accelerant. If you are particularly sensitive to caffeine, you may want to either take very small doses of this supplement or avoid it altogether. If you want to give this supplement a try, it is best to look for a product which is standardized for 50% chlorogenic acid, the primary active ingredient. The dose probably required to see some results is 300 milligrams twice daily, taken with water before meals. While drug interactions and side effects are few and generally minor, green coffee extract, especially in larger doses, can give you stomach upset and diarrhea. You can purchase 90 capsules containing 200 milligrams of 50% chlorogenic acid standardized each from Vitacost at $5.99, making this one of the least expensive weight loss supplements. Sadly, contrary to representations made by media celebrity Dr. Mehmet Oz, green coffee has not been shown to be as effective as green tea and other supplements at facilitating weight loss.

CLA (Conjugated Linoleic Acid)

CLA (conjugated linoleic acid) is a naturally occurring fatty acid which, ironically, may assist in weight loss unaided by exercise. It is found in the meat of ruminant animals such as cows and sheep, but is generally sourced through safflower, sunflower and other vegetable oils. CLA probably owes its weight loss properties to its action in breaking down fats and slowing down the creation and accumulation of body fat. Weight loss among individuals using CLA continuously and consistently for periods in excess of six months has been very modest, but better than the results in individuals taking a placebo. The recommended dose of CLA is between 2,400 and 6,000 per day. At this dose level, CLA is generally well tolerated and considered to be safe. 


Glucomannan is a water-soluble dietary fiber (a polysaccharide) derived from the root of the konjac plant, or elephant yam, which is used as an emulsifier and a thickener in food products. As a dietary supplement, it is generally taken in the form of capsules, tablets or powder. It owes its beneficial effect to its absorption of water and stomach fluids and expansion to create a feeling of fullness; in this way it serves as a harmless appetite suppressant. Glucomannan, taken with copious amounts of water, is also an effective natural laxative. Both of these attributes contribute to its efficacy as an aid to weight loss. In addition, glucomannan may reduce the absorption of cholesterol, sugars and some fats in the gut, such that these are excreted instead of fully digested and metabolized. Taking glucomannan along with medications taken by mouth can decrease how much medicine the body absorbs. To prevent this interaction, take glucomannan at least one hour after any medications you have taken by mouth. A safe but effective dosage of glucomannan is between 3,000 milligrams and 4,000 milligrams daily, taken with water prior to mealtime. At this dosage level, and for periods of up to four months, glucomannan seems to be a very safe supplement, especially if you have a tendency to overeat. At higher dosage levels, glucomannan can give you stomach upset and diarrhea, so it is best not to overdo it.

Garcinia Cambogia

Garcinia cambogia is a fruited plant native to Southeast Asia. It is sometimes alternately referred to as brindle berry and malabar tamarind. It is used as an ingredient in curries, sauces, and flavorings. The potential source of garcinia cambogia’s supposed benefits is its hydroxycitric acid (HCA) content. This substance, which is also sold in its isolated and purified form as a dietary aid, is said to suppress appetite and block fat so that it is not absorbed, and is, instead, excreted. There is considerable scientific evidence to support these claims, although the actual effectiveness of garcinia cambogia is something short of miraculous, despite the grinning enthusiasm of television’s celebrity diet doctors. Still, it is worth a try, with a few small caveats. 

Its interactions with prescription drugs and other supplements are minimal, and side effects, such as stomach ache and nausea, generally occur only in cases where excessive doses are taken. If you are taking an antidepressant which acts to increase serotonin levels (or the intersynaptic proliferation and duration of serotonin) you should use caution taking this supplement, as it may increase the risk of serotonin syndrome and cardiac issues. 

With that caution in mind, a safe, effective dose is between 1,000 and 1,800 milligrams of garcinia cambogia daily (depending on your body weight and other factors), taken before a meal. Garcinia cambogia supplement formulations often include chromium, which acts synergistically with garcinia cambogia, or small proportions of potassium, which serves to increase its bioavailability. A wide variety of formulations, both with and without these secondary ingredients, can be found at Vitacost. This is a relatively inexpensive supplement and it is probably safe to try using a graduated dosage approach, e.g., where you start with a low dose and work up, over time, to a regular, standard dose. Once again, use this supplement with caution, and at the lower end of the effective range of dose, if you are taking antidepressant medications such as tricyclics and SSRIs.

7-Keto DHEA

7-keto-dehydroepiandrosterone (7-keto DHEA) is a weight loss supplement which may work through stimulation of the metabolism and increasing the body’s resting caloric burn rate as a thermogenic agent. DHEA, the root molecule of 7-keto DHEA, is naturally secreted by the adrenal cortex of the kidneys and is a steroid precurser to sex hormones such as testosterone and estrogen. While 7-keto DHEA is a related compound, it does not have the potential to increase the concentrations of these hormones in the bloodstream or the body, and is estimated to be more than two and a half times as thermogenic as its sexier parent (…you’d think that it might be the other way around). 7-keto DHEA is also thought to play a role in dampening the effect of a hormone which facilitates the conversion of cortisone into cortisol, and cortisol is responsible for diet- and exercise-resistant accumulation of weight, especially around the middle of the body. 

The recommended dosage of 7-keto DHEA is from 100 milligrams to 200 milligrams twice daily, taken with water. This supplement is available in capsule form, generally in a serving size of 100 milligrams, although smaller dosages per capsule are available from NOW Supplements. 7-keto DHEA is generally regarded as safe, having very few interactions with medications and other supplements, and without any major reported side effects with the exception of nausea and a metallic aftertaste at significantly higher doses than those recommended earlier.


Resveratrol is a polyphenol compound found in the skin of grapes, in red wine, and in an Asian plant called Polygonum cuspidatum. There is a growing body of evidence that this substance can facilitate weight loss and inhibit the accumulation of fat in the body through a combination of effects, including the suppression of insulin resistance, the activation of the SIRT1 gene (which is thought to protect the body against some of the ravages of obesity and aging), and certain other indirect or secondary effects that are still being researched and evaluated. Resveratrol also has demonstrated significant antioxidant and anti-inflammatory properties, which make it a high-value component of any anti-aging and longevity supplement stack. 

If you take NSAIDs or other medications which reduce blood clotting, resveratrol will likely increase their effects, so exercise caution. Additionally, taken in high doses, resveratrol may slow down the clearance of some blood pressure medications from the body, thereby enhancing and prolonging their effects, which can potentially reduce blood pressure to dangerous levels. As with all supplements, it is a good idea to speak with you health care provider before starting supplementation with resveratrol.

Aside from these drug interaction precautions, resveratrol is generally safe when taken in effective doses of between 500 milligrams and 2,000 milligrams daily, and side effects (mostly having to do with gastrointestinal issues and nausea) are few and rare.

Since oral supplements of resveratrol are somewhat inefficent due to resveratrol’s characteristically low bioavailability, it is a good idea to pair it with quercetin, which facilitates better absorption into the bloodstream. Due to its multiple benefits on various physiological fronts, resveratrol might be worth a try if you are not already supplementing with it.   

Getting started

In custom-bulding a weight loss stack with some of the ingredients discussed earlier in this article, you can shop item by item across multiple sites for multiple suppliers, or you can save some time and shipping expense by consolidating your search to one selected e-commerce retailer. Vitacost has all of the ingredients covered in this article at the lowest average price per item in the marketplace, and with what would seem to be the greatest variety of forms and dosages generally available anywhere. Additionally, as a matter of policy, and in keeping with a sense of social responsibility, Vitacost’s featured brands are all natural, organic and sustainably sourced.

Weight Loss Supplements

Weighing in on supplements

The research and scientific validation regarding these non-prescription and largely naturopathic ingredients is largely murky or inconclusive for the reasons cited at the beginning of this article, but insofar as most of these supplements are reasonably safe (paying attention to the caveats mentioned in the sections regarding each of them) and affordable, trying them is certainly an option. Of course, supplementation is not a panacea – there is no substitute for proper diet (e.g., making healthful food choices), reduced caloric intake, adequate rest, cardiovascular exercise and resistance exercise. And these things should be undertaken subject to the advice and supervision of the appropriate health care professionals and trainers.
Supplementation is, as the term itself implies – something to be done in addition to leading a healthy lifestyle. When it comes to weight loss, there are no quick fixes in the form of non-prescription supplements. Having said this, supplements can accelerate and increase weight loss when used as an adjunct to better choices and a consciously healthy lifestyle.


Important Note: This article does not contain health or medical advice, and the information contained herein is not intended to diagnose, prevent, treat or cure any disease, condition or health problem. Before beginning any program of diet, nutrition or supplementation, seek the advice of a competent healthcare professional in order to determine the possible effects on your health, given your individual sensitivities, needs and objectives.

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