Hydroxycitric acid (HCA) is a major acid component of the tropical plants  - a plant native to Southeastern Asia - Hibiscus subdariffa and a few other plants. The availability of hydroxycitric acid is limited by the restricted habitat of the plants as well as the difficulty of making hydroxycitric acid in the laboratory.

Buy Hydroxycitric acid, see Garcinia Cambogia

Diet Rx natural appetite suppressant with hydroxycitric acid
If you would like to eat less, consider a product called Diet Rx with green tea extract, hoodia extract, hydroxycitric acid and effective diet herbs and extracts. This natural appetite suppressant works without stimulants. Diet Rx has no added caffeine, ephedra, ephedrine alkaloids, synephrine, hormones, guarana, ginseng, or stimulating amino acids. 

All natural appetite suppressant, decreases appetite so you eat less
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Helps you maintain healthy cholesterol and lipid levels
Improves energy
Balances mood
Improves mental concentration and focus
Improves will power and choice of food selection

Hydroxycitric acid in Garcinia Cambogia
Hydroxycitric acid is found in a high concentration - ranging from 10 to 30% - in the dried fruit rind of Garcinia cambogia. The dried rind has been used for centuries throughout Southeast Asia as a food preservative, flavoring agent and carminative. Extensive experimental studies show that Hydroxycitric acid inhibits fat synthesis and reduces food intake.

How it works
The primary mechanism of action of hydroxycitric acid appears to be related to its ability to act as a competitive inhibitor of the enzyme ATP-citrate lyase, which catalyzes the conversion of citrate and coenzyme A to oxaloacetate and acetyl coenzyme A (acetyl-CoA), primary building blocks of fatty acid and cholesterol synthesis.
     Hydroxycitric acid from Hibiscus subdariffa inhibits alpha-amylase and alpha-glucosidase, leading to reduction of carbohydrate metabolism.

Hydroxycitric Acid HCA and Weight Loss
This substance has been reported to promote body fat loss in humans without stimulating the central nervous system. The level of effectiveness of G. cambogia extract is typically attributed solely to hydroxycitric acid. However, other components may contribute to its therapeutic effectiveness. Results thus far with hydroxycitric acid and weight loss appear to be promising.

J Clin Diagn Res. 2015. Efficacy of garcinia cambogia on body weight, inflammation and glucose tolerance in high fat fed male wistar rats. Supplementation of the Garcinia Cambogia extract with high fat diet reduced body weight gain, inflammation and glucose intolerance.

Efficacy of a novel calcium/potassium salt of hydroxycitric acid in weight control.
International J Clin Pharmacol Res. 2005
The weight-loss efficacy of a novel, water-soluble, calcium-potassium salt of hydroxycitric acid was re-examined in 90 obese subjects (BMI: 30-50.8 kg/m2). We combined data from two previously reported randomized, double-blind, placebo-controlled clinical studies in order to achieve a better statistical evaluation based on a larger population. This re-examination of data also allowed us to reflect more intensely on various aspects of weight loss studies. Subjects were randomly divided into three groups: group A received a daily dose of hydroxycitric acid 4, 667 mg (providing 2,800 mg hydroxycitric acid per day); group B was given a daily dose of a combination of hydroxycitric acid 4,667 mg, niacin-bound chromium (NBC) 4 mg (providing 400 microg elemental chromium), and Gymnema sylvestre extract (GSE) 400 mg (providing 100 mg gymnemic acid); and group C received a placebo in three equally divided doses 30-60 min before each meal. All subjects were provided a 2,000 kcal diet/day and participated in a supervised walking program for 30 min/day, 5 days/week. Eighty-two subjects completed the study. At the end of 8 weeks, in group A, both body weight and BMI decreased by 5%, low-density lipoprotein and triglycerides levels were reduced by 12% and 6%, respectively, while high-density lipoprotein levels increased by 8.9%, serum leptin levels decreased by 38%, serotonin levels increased by 44% and urinary excretion of fat metabolites increased by 32-109%. Group B demonstrated similar beneficial changes, but generally to a greater extent. No significant adverse effects were observed. The combined results confirm that hydroxycitric acid and, to a greater degree, the combination of hydroxycitric acid plus NBC and GSE reduce body weight and BMI, suppress appetite, improve blood lipid profiles, increase serum leptin and serotonin levels and increase fat oxidation more than placebo. We conclude that dosage levels, timing of administration, subject compliance and bioavailability of hydroxycitric acid significantly affect results and that when taken as directed, hydroxycitric acid is a highly effective adjunct to healthy weight control.

Effects of a natural extract of hydroxycitric acid (HCA-SX) and a combination of HCA-SX plus niacin-bound chromium and Gymnema sylvestre extract on weight loss.
Diabetes Obes Metab. 2004.
The efficacy of optimal doses of highly bioavailable hydroxycitric acid alone and in combination with niacin-bound chromium (NBC) and a standardized Gymnema sylvestre extract (GSE) on weight loss in moderately obese subjects was evaluated by monitoring changes in body weight, body mass index (BMI), appetite, lipid profiles, serum leptin and excretion of urinary fat metabolites. hydroxycitric acid has been shown to reduce appetite, inhibit fat synthesis and decrease body weight without stimulating the central nervous system. NBC has demonstrated its ability to maintain healthy insulin levels, while GSE has been shown to regulate weight loss and blood sugar levels. A randomized, double-blind, placebo-controlled human study was conducted in Elluru, India for 8 weeks in 60 moderately obese subjects (ages 21-50, BMI >26 kg/m(2)). Subjects were randomly divided into three groups. Group A was administered hydroxycitric acid 4667 mg, group B was administered a combination of hydroxycitric acid 4667 mg, NBC 4 mg and GSE 400 mg, while group C was given placebo daily in three equally divided doses 30-60 min before meals. All subjects received a 2000 kcal diet/day and participated in supervised walking. At the end of 8 weeks, body weight and BMI decreased by 5-6% in both groups A and B. Food intake, total cholesterol, low-density lipoproteins, triglycerides and serum leptin levels were significantly reduced in both groups, while high-density lipoprotein levels and excretion of urinary fat metabolites increased in both groups. A marginal or non-significant effect was observed in all parameters in group C. The present study shows that optimal doses of HCA-SX and, to a greater degree, the combination of hydroxycitric acid, NBC and GSE can serve as an effective and safe weight-loss formula that can facilitate a reduction in excess body weight and BMI, while promoting healthy blood lipid levels.

Safety, toxicity, danger
Thus far I am not aware of major side effects or liver harm when this product is used by itself.

World J Gastroenterol. 2013. Hydroxycitric acid does not promote inflammation or liver toxicity. Garcinia cambogia extract (GC) with its active component consisting of hydroxycitric acid (HCA) is widely utilized for weight loss. Various HCA salts are available, including calcium, magnesium, potassium and mixtures of these. Experimentally, these salts exhibit different properties with some, but not all, improving glucose tolerance and blood pressure. Recently, obesity-prone C57BL/6J mice were fed a high-fat diet (HFD, 45 kcal% fat) with or without GC (1%, w/w) for 16 wk. The active arm reduced visceral fat, adipocyte size and serum glucose, yet purportedly also exhibited hepatic collagen accumulation, lipid peroxidation and increased mRNA levels of genes related to oxidative stress. The latter findings are at odds with a large body of animal and human studies that have been conducted on the safety and efficacy of HCA. This literature shows HCA to be protective against the liver toxicity associated with ethanol and dexamethasone administration, and to maintain serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase at near normal levels. In both animal and clinical literature, elevated intakes of HCA per se have not led to signs of inflammation or hepatotoxicity. The compound has been found to reduce markers of inflammation in brain, intestines, kidney and serum.

Safety assessment of hydroxycitric acid and Super CitriMax, a novel calcium/potassium salt.
Food Chem Toxicol. 2004. Burdock Group, Vero Beach, FL
There is sufficient qualitative and quantitative scientific evidence, including animal and human data suggesting that intake of HCA at levels up to 2800 mg/day is safe for human consumption.

I love your work and your products, I have a question regarding hydroxycitric acid, On your webpage a pharmacist wrote in to ask you if this compound is known to create liver damage and you stated that you did not see any research regarding that fact. I googled "hydroxycitric acid and liver damage" and found numerous reports that blame hydroxycitric acid for liver damage and even one death caused by liver failure by someone taking this product. Would you and your staff take a look at this latest information and tell your readers if you think this product is in fact a danger to the liver.\
   A review in 2013 of all published studies did not reveal liver damage as a result of HCA consumption. There are reports of people taking Hydroxycut, a formula with many ingredients including HCA, that has caused liver damage, but one cannot blame one of the ingredients in the formula as being the culprit. The product had high doses of chromium, could this mineral have been one of the culprits?

Research
Comparison of the effects of three different hydroxycitric acid preparations on food intake in rats.
Nutr Metabolism. 2005.
s differences in the hydroxycitric acid preparations may contribute to this apparent discrepancy, the aim of the current study is to compare different hydroxycitric acid -containing preparations in adult Wistar rats. The effects of 3 different hydroxycitric acid -containing preparations (Regulator, Citrin K, Super CitriMax HCA-600-SXS, all used at an effective hydroxycitric acid dose of 150 and 300 mg/kg, administered intragastrically) on food intake and body weight were studied in adult male Wistar rats. The efficacy was tested under 2 different experimental conditions: 1) after a single dose administration and 2) during repeated administration for 4 subsequent days. Regulator and Citrin K significantly reduced food intake in both experimental setups, while Super CitriMax HCA-600-SXS was less effective. When administered for 4 subsequent days Regulator and Citrin K diminished body weight gain. CONCLUSION: Regulator and Citrin K were shown to be potent inhibitors of food intake in rats, whereas Super CitriMax HCA-600-SXS showed only small and more inconsistent effects. The striking differences in efficacy between these 3 preparations indicate that low doses of a relatively low-effective hydroxycitric acid preparation may have contributed to the lack of efficacy as found in several human studies.

Hydroxycitric acid delays intestinal glucose absorption in rats.
Am J Physiol Gastrointest Liver Physiol. 2005.
In this study, we investigated in rats if hydroxycitric acid (HCA) reduces the postprandial glucose response by affecting gastric emptying or intestinal glucose absorption. We compared the effect of regulator hydroxycitric acid (310 mg/kg) and vehicle (control) on the glucose response after an intragastric or intraduodenal glucose load to investigate the role of altered gastric emptying. Hydroxycitric acid treatment decreased concentrations of [U-(14)C]glucose in small intestinal tissue at 15 min after [U-(14)C]glucose administration, in accordance with the concept that hydroxycitric acid delays the enteral absorption of glucose. These data support a possible role for hydroxycitric acidas food supplement in lowering postprandial glucose profiles.

Effect of hydroxycitrate on respiratory quotient, energy expenditure, and glucose tolerance in male rats after a period of restrictive feeding.
Nutrition. 2004.
Recently we demonstrated that hydroxycitrate (HCA) suppresses food intake and body weight regain in male rats after substantial body weight loss. However, it is not known whether Hydroxycitric acid also affects the respiration quotient (RQ), energy expenditure (EE), and glucose tolerance in this animal model. Twenty-four male rats (initial body weight, 378 +/- 3 g) were fed restrictively (10 g/d) for 10 d and then given ad libitum access to a high-glucose diet supplemented with 3% HCA for 6 d. Controls received the same diet without the supplement. RQ and EE were measured during ad libitum days 1, 2, and 6. An oral glucose tolerance test was performed on ad libitum day 4 or 5. HCA decreased RQ and EE during ad libitum days 1 and 2. In all probability, these findings reflect a decrease in de novo lipogenesis. On ad libitum day 6, RQ and EE did not differ between treatment groups. Hydroxycitric acid suppressed food intake during the first 3 d ad libitum, but overall body weight regain was not decreased in the Hydroxycitric acid group. The oral glucose tolerance test showed that Hydroxycitric acid significantly decreased the increase in plasma glucose from baseline (Deltaglucose) and tended to decrease the area under the curve for glucose. Deltainsulin and area under the curve for insulin did not differ between groups. Our results indicate that, in this animal model, Hydroxycitric acid suppresses de novo lipogenesis. Moreover, Hydroxycitric acid may improve glucose tolerance.

Questions
Q. I have type 2 diabetes. In addition to my prescription treatment, I have added some natural products. The hydroxycitric acid HCA product helped me feel a lot better. However, after about a year, I became allergic (itching). I suspect that my allergy is due to plant extracts that accompany the HCA.
   A. It is often a good idea to take a break from most supplements in order to avoid tolerance, allergy, or excess exposure.

Q. When I discovered that I had type 2 diabetes I started taking an hydroxycitric acid HCA supplement. I could not believe how good I felt on the supplement. However, after several months, I started itching and found that I had developed an allergy to something in the supplement. I tried some other brands and they all employed a form of hydroxycitric acid HCA that was extracted from Garcinia Cambogia. I found that I had an allergic reaction to all of them. I think that my allergy may be due to an impurity that extracts along with the HCA. I really doubt that I could be allergic to hydroxycitric acid Is there an alternate plant source or a chemically pure form that I could try? What do you think?
   A. It is possible that hydroxycitric acid caused the itching but we cannot be sure. We have not seen long term trials with this supplement given for many months or years. We are not aware of another over the counter product whose source of hydroxycitric acid is other than GC, as of 2013.

I am looking to lose weight and have read up on HCA in research journals. Thank you for writing about it. Can you recommend a specific brand to purchase from that you know is trustworthy (aka not a scam or has fillers)? I was reading some studies and this combo was the best one I found: HCA-SX 4,667 mg, NBC 4 mg (providing 400 μg elemental Cr) and GSE 400 mg (providing 100 mg gymnemic acid).
   I have not done personal testing of different products to know for certain which are the best.

Products on sale online
Natrol Pure Citrimax, 250 mg., buy Hydroxycitric Acid HCA
Natrol's Pure CitriMax is derived from the dried rind of Garcinia Cambogia, a native fruit of India. CitriMax contains high concentrations of hydroxycitric acid, verified by HPLC to guarantee potency and quality.
CitriMax Supplement Facts:
Hydroxycitric Acid HCA - 250 mg
     (Standardized Extract from Garcinia cambogia [fruit])