Labdoor analyzed 29 best-selling G. cambogia herbal supplements in the United States, measuring levels of the key active ingredient, hydroxycitric acid (HCA), as well as heavy metal content (antimony, arsenic, bismuth, cadmium, and silver).
Inaccurate label claims were a major trend in this category, with the vast majority of tested products (21/29) recording negative label claim variances. Of the 21 products recording less HCA content than claimed, 12 products recorded at least 75% less HCA and 9 products recorded at least 85% less HCA than claimed.
Samples of every Garcinia supplement passed all six heavy metal assays. Products received reduced Ingredient Safety ratings for the presence of key watchlist ingredients, including two coloring agents (FD&C Red 40 and titanium dioxide) and controversial preservatives (benzoates).
Actual hydroxycitric acid (HCA) content ranged from -99.5% to +32.2% vs. the products stated label claims.
The average product deviated off its HCA claim by 47.8% (average absolute variance) and was more likely to record an active ingredient underage. 21/29 products recorded less HCA than claimed, 13 of which saw true HCA content measure at least 50% below their claims and 9 of which saw true HCA content measure at least 85% below their claims. Worst offender: Trusted Nutrients Garcinia Cambogia, which recorded just 3.09 mg of HCA per serving, 99.5% below its label claim.
All products in this report were screened by Inductively Coupled Plasma (ICP)-based techniques for the presence of heavy metals. Samples of each product passed all six heavy metals assays, indicating that samples contained under 1 PPM (part per million) each of arsenic, lead, cadmium, bismuth, antimony, and silver compounds.
Labdoor's Nutritional Value calculations are largely based on macronutrient ratios, with added sugars, sodium, and cholesterol being penalized in this rating. Most Garcinia supplements recorded low values across the board here.
At 5g of added sugars and 30 calories per serving, Purely Inspired Garcinia Cambogia Gummies recorded the highest value for both attributes.
Labdoor’s Ingredient Safety calculations are based on two key factors: active ingredient dose as well as presence and severity of key heavy metals and added excipients.
Currently, both animal and human studies have not indicated any observable toxic or mutagenic effects as a result of oral HCA supplementation. Further research is needed.
The majority of product were watchlist ingredient-free. However, we did note the presence of the preservative benzoic acid, the artificial color FD&C Red No. 40, and opacity-providing coloring agent titanium dioxide in 4/29 tested products.
HCA, the primary active ingredient responsible for G. cambogia’s weight-loss effects, is suggested to work primarily by reducing de novo lipogenesis, the process during which carbohydrates are converted into fat (via the competitive inhibition of the enzyme citric acid lysase). Studies have also suggested that HCA may help suppress appetite (by regulating levels of the neurotransmitter serotonin, which plays a role in satiety.) These claims have been replicated in animal studies.
Available studies assessing the effects of Garcinia cambogia on weight loss in humans have shown variable results, with the majority failing to produce significant weight loss/fat mass loss beyond that observed in the studies’ respective placebo groups.
In one study, 2.4 g per day of Garcinia cambogia (50% HCA, taken 30-60 minutes prior to meals) over the course of 12 weeks resulted in an extra 1.3 kg (2.9 lb) loss over placebo in overweight women (n = 42). In separate studies, 2 g Garcinia cambogia (60% HCA) given daily for 10 weeks and 3 g Garcinia cambogia (50% HCA) given daily for 12 weeks had no significant effect on weight loss or appetite suppression. In all studies, all participants (intervention and control groups) were asked to follow similar restrictive diets.
4/29 tested products in this batch exceeded 1000 mg HCA per serving. The category’s best performer, Islands Miracle Pure Garcinia Cambogia, recorded 1195 mg of the active ingredient in a single serving. 9 products recorded less than 100 mg HCA per serving.
It should be noted that research into the efficacy (and safety) of garcinia extract in humans is still relatively nascent, with the majority of studies involving small sample sizes and short treatment durations. In fact, there have been no human studies exceeding 12 weeks of intervention. Further research is needed to better understand the spectrum of effects of supplemental garcinia extract.