Have you heard of the HCG diet? It’s been around for over 60 years. I first heard of this diet in 2007 in a book called “The Weight Loss Cure They Don’t Want You to Know About”. What I would like to do here is review the scientific studies that have been performed on the HCG diet protocol and let you draw your own conclusions about whether HCG injections help weight loss or not. This review will focus on the original version of HCG diet – the version that uses injections of the hormone HCG. I’ve also written a review of homeopathic HCG (HCG drops). I suggest you read this review of the original HCG diet protocol first and then check out the info on HCG drops for a more full picture.
What is the HCG diet?
HCG stands for human chorionic gonadotropin. This is a hormone that women make when they are pregnant. In fact the most natural way to raise HCG levels is to get pregnant.
The HCG diet dates back to about 1954 when a doctor named Albert Simeons started giving HCG injections to obese people. He published his study in the Lancet, a well known medical journal.
The HCG diet basically consists of daily HCG injections coupled with a 500 calorie diet. In addition people are also told to refrain from using hardly any fat. Even the fats in cosmetics are to be avoided during the HCG diet. There are many HCG diet books to help people with the food portion of the program.
According to Simeons, giving HCG along with the 500 calorie diet was better for weight loss than just giving them 500 calories. He claimed that his technique achieved fast weight loss without people being hungry. This he said was because HCG suppressed the appetite and enhanced people’s moods.
HCG injections also were alleged to burn fat from specific areas of the body. Today we would call this claim “spot reduction” – ridding fat from only certain locations like troublesome areas of the thighs for example.
It’s my understandings that in Kevin Trudeau’s weight loss book, he speculated that HCG stimulated the hypothalamus of the brain to get the body to start burning fat. Whether that’s true or not doesn’t matter.
What matters is that Dr. Simeons claimed that the HCG diet could result in weight loss of between ½ lb and almost 2 lbs per day on average.
HCG Diet Research
There is HCG diet research. From what I can discover, scientists have looked this diet several times since the early 1960s. I want to summarize this diet research because the HCG diet books probably won’t tell you about it.
Where possible I have also linked to the actual scientific studies so you can read them for yourself if you like. Let’s now briefly summarize the HCG research:
In 1963 Craig and associates tested the Simeons diet in 20 overweight women. The study lasted 45 days. Women were split into 2 groups:
- one group received daily shots of HCG (125 units)
- the other received shots of a placebo
All women ate only 550 calories a day contained in 2 meals. Women could drink as much water, tea or coffee they liked (no sugar in tea or coffee).
Results: Women getting HCG injections did not lose more weight.
In 1973, Asher and Harper tested the HCG diet in 40 overweight women for 6 weeks. The study was published in the American Journal of Clinical Nutrition.
Women either received either
- daily HCG injections (125 units)
- or a saline placebo.
All women consumed a 500 calorie diet.
Results. Asher and Harper found that women getting HCG injections lost more weight than those who received a placebo.
In the study, it was stated that Harper, who did the “clinical work” also “has an active practice using HCG for weight reduction”. In science, this is technically a no no. Some might see this as possible bias (even unconscious bias) on the part of the researcher.
However, the connection of the researcher to the HCG diet was clearly disclosed at the beginning of the study. They were not trying to hide this and I will call this study a “win” for the HCG diet.
It was because of the findings by Asher and Harper that in 1976, Stein and colleagues decided to test the HCG diet. In their investigation, they used a similar protocol as Asher and Harper (Asher provided Stein with their research design).
They tested the HCG diet in 51 young women (ave age 33). The study lasted 32 days. Women were split into 2 groups:
- One group received daily injections of HGC (125 units)
- The other group received injections of a saline placebo
All women were put on the identical 500 calorie diet as in the Asher and Harper study. Women were also instructed to drink 8-10 glasses of water per day.
Results. This study found that the HCG diet did not help weight loss.
Women getting HCG did not lose any more weight than those getting the placebo. In addition, women getting HCG injections did not lose more weight in specific areas of the body (as the HCG diet proponents often say will happen).
Also in 1976, another HCG study was performed by Young and colleagues. In this study, there were 202 people.
For 6 days a week, people received either
- injections of HCG (125 units a day)
- or saline injections (placebo)
In addition people also ate 500 calories a day and received lectures on diet and behavior modification twice a week for the length of the study.
All fat was excluded from the diet except for the fat that was associated with the protein that people ate from food.
This study also tested whether HCG treatment helped people maintain their weight loss better. This was accomplished by giving people 6 weeks of no HCG injections coupled with education about how to eat properly.
Results. At the end of the study, researchers found that HCG injections did not lead to any greater weight loss or weight maintenance than those who did not get HCG injections. In the words of the researchers:
“… we could not demonstrate by any objective indicator that HCG was beneficial in promoting weight loss, nor was there any significant difference in fat loss or body circumference measurements”
In 1977, Shetty and Kalkhoff did a small study of HCG in 6 hospitalized obese women. The women were only given 500 calories a day and injected daily with 125 unites of HCG for 30 days. Another 5 women were given the exact same diet yet injected with a placebo.
Results. According to the authors, weight loss between groups was “nearly identical”. Measurements of the circumferences of the chest, waist, hips or thighs also showed no differences between the HCG and placebo groups. Any changes observed, the authors noted, was consistent with “semi starvation” and weight loss”.
Also in 1977 Greenway and associates, tested the HCG diet for 6 weeks in 40 healthy women (age 20-40) who were randomly divided into 2 groups:
- One group received HCG
- The other group got a placebo
Both groups received injections 6 days a week for 6 weeks. Greenway did not specify how much HCG women received in their investigation (I’ll assume it was 125 units but I cannot prove this).
Results. People getting daily HCG injections did not lose any more weight than women who received a placebo. Likewise, there were no differences in body circumferences or mood in those who received HCG injections. The Greenway study was concluded with these words (note these words were written in 1977):
“We feel that the 20 year history of the use of HCG in the treatment of obesity should come to an end because injections of placebo appear to be equally effective in all respects.”
In 1983 Birmingham and Smith reviewed 6 of double blind studies of the HCG diet conducted at that time.
Results. They concluded that only one study (the Asher and Harper study mentioned above) found that HCG injections caused weight loss more than placebo. The other 5 studies found that HCG injections do not cause weight loss.
In 1990, Venter and associates tested the HCG diet in 40 obese women for 6 weeks. In this double blind placebo controlled study, women were either given daily HCG injections or injections of a placebo. All women were put on the same diet that supplied 1200 calories a day.
Before and after the study, they tested body weight body circumferences and hunger level.
Results. The HCG diet “showed no advantages over those on placebo in respect any of the variables recorded”. So HCG didn’t work.
In 1995, Lijesen and colleagues performed a meta-analysis of 24 previously published HCG diet studies.
A meta analysis basically means that the researchers added together the results of a bunch of studies, to see if they could find “the big picture”.
Results. They concluded that “there is no scientific evidence that HCG is effective in the treatment of obesity”
“it [HCG] does not bring about weigh loss or fat redistribution nor does it reduce hunger or induce a feeling of well being.”
Summaries of HCG weight loss studies
|Study||People in study||Study design||Results|
|Craig (1963)||20||Double blind placebo controlled||HCG doesn’t work|
|Asher/Harper (1973)||40||Randomized double blind||HCG works|
|Stein (1976)||51||Randomized double blind||HCG doesn’t work|
|Young (1976)||202||Randomized double blind cross over||HCG doesn’t work|
|Sheety (1977)||6||Randomized double blind||HCG doesn’t work|
|Greenway (1977)||40||Randomized double blind||HCG doesn’t work|
|Birmingham (1983)||358||Meta analysis of 6 HCG studies||HCG doesn’t work|
|Lijesen (1995)||?||Meta analysis of 24 HCG studies||HCG doesn’t work|
Note. This is just a sample of the HCG weight loss studies. There are several others.
My friend and colleague, Dr. Bill Sukala, has written good science based review of the HCG diet research if you want additional info on the science of the HCG diet plan.
HCG Diet and the thyroid
Some ask if the HCG diet can help the metabolism or thyroid or improve hypothyroidism. I am not aware of any research that looked at the HCG diet protocol and checked to see if it altered the level of thyroid hormone or altered TSH levels. As people lose weight -though any diet – metabolism does tends to decrease. This is why its often easier to lose the first 50 pounds than the last 10 pounds of weight. Whether or not HCG can alter this is something I feel needs some research.
Related to this, people to advocate the HCG diet protocol often say that HCG injections (and HCG drops) help people preserve muscle during weight loss. Again, I have not seen any scientiif proof that HCG injections or oral HCG drops reduces muscle loos when dieting. Theoretically eating only 500 calories per day would eventually cause the body to start cannibalizing itself to maintain adequate energy. Whether HCG injections can reduce/reverse this process is unknown as far as I can tell and is likewise deserving of research. These 2 aspects of the HCG diet would make for very interesting grad student research…
HCG Diet Research: So where does this leave us?
Some say that HCG needs to be used soon after being prepared or it becomes useless. Could this be why all the other HCG studies show it doesn’t work? Could all the other researchers have made a critical mistake?
Maybe. In theory there may be something to this- if HCG really does break down as fast as they say.
Could there be a conspiracy by the medical community to prevent people from knowing the truth about HCG? I don’t think so. Here’s why.
Covering up proof that the HCG diet works would be very difficult because EVERYBODY can read the HCG diet studies. ANYBODY can replicate the studies today using the very same procedures and see if it works.
So why don’t the sellers of the HCG diet protocol – instead of invoking the name of Alebert Simeons– do their own HCG diet research, publish that research and prove to the world that the HCG diet really works?
What do you think?