Garcinia Cambogia is likely ineffective.  

Garcinia cambogia

If you pick up a checkout counter magazine, there is not or listened to Dr. Oz on TV, you know about Garcinia cambogia.   Garcinia cambogia (malabar tamarind, bitter kola) is a herb or supplement that is all the rage for weight loss.  This plant source for this herb is abundantly in the evergreen forests of Konkan in South India.  In fact, I wrote an article about it: Supplements: Garcinia Cambogia Extract.  In this article, I high lighted the risks and suggested that probably safe was not worth the benefit of the mild temporary weight loss.  

There is new research to indicate that it is ineffective to go along with the potential for harm.  Hydroxycitric acid is the active ingredient in Garcinia Cambogia.  It was identified by the end of the 1960’s, but was not reach for weight loss fame until Dr. Oz has it on his show in about 2014.  After which, every star on TV and every rag at the checkout counter began touting it as a weight loss miracle.  

The new study was released in 2018[1].  The objective of the study was to look at the effect of Garcinia cambogia extract known as a supportive agent in weight loss through the hunger hormones (leptin, ghrelin, adiponectin, insulin).  The research was performed in obese rats.  The rats were fed the diet containing hydrogenated-vegetable oil and cholesterol.  Each test group consisted of 10 rats.   Group 1 (as a control group) was fed with a basal diet while the diets of Groups 2 and 3 contained the hydrogenated-vegetable oil (20%) and cholesterol (1%) beside of other nutrients.  Garcinia cambogia extract containing 6% hydroxycitric acid was added to the diet of Group 3 for 30 days (days 30-60).  

To test for the hunger hormones, blood samples were taken from animals on Days 0, 30 and 60 of the trial period.  Body weights were weighed in the blood sampling days before sampling.  Unfortunately, Serum leptin, ghrelin, adiponectin, insulin levels, and body weights were not significantly different between groups in each test days.  In fact, serum leptin levels were significantly higher on Day 60 than on Days 0 and 30 in Groups 2 and 3.  Serum ghrelin levels in Group 3 significantly decreased on Day 30 and significantly increased on Day 60.  The serum insulin levels and body weights were not significantly different between the days in each group.  

We would have expected that leptin levels would decrease, ghrelin would increase, and insulin would decrease with weight loss or a fatty diet.  Only a small part of this was true.  If Garcinia cambogia effects hunger or metabolism, we would have expected a stronger response or some response at all.  There was not a significant difference between the three groups.  

The bottom line:  The high lipid diet in doses used in the study did not create fat accumulation or obesity in rats.  Addition of Garcinia cambogia to the diet of rats fed with the high lipid diet indicated it has no effect on weight.  The evidence obtained from this research does not support the role of Garcinia cambogia as a weight loss modulator.  I stick by my recommendation to avoid it.  It is just not worth the risk.