How Long Does HCG Shot Stay in Bloodstream?

HCG is a naturally occurring human hormone that has been FDA-approved for treatment of a number of conditions over the years. Since the middle of the last century, though, certain weight-loss clinics have also administered the substance as a purported weight-loss aid. In recent years, it has quickly grown in popularity for that purpose, and is usually administered as injections or as sub-lingual drops.

What is HCG?

HCG stands for human chorionic gonadotropin. It's a glycoprotein hormone produced in a woman's body during pregnancy, both by the embryo and the placenta. It aids in the production of the fellow hormone progesterone, which thickens the uterus and helps to nourish the fetus. HCG is one of the hormones detected by most pregnancy tests.

History as a Weight-Loss Aid

In the 1950s, the British endocrinologist A.T.W. Simeon began experimenting with the use of HCG for weight loss. While studying pregnant women in India, he noticed that those on a calorie-deficient diet lost fat mass rather than muscle. He hypothesized that it was the HCG which helped mobilize the fat, as one of HCG's roles is also to destroy abnormal fatty tissues in a fetus. He summarized his findings in a book called "Pounds and Inches," and began administering HCG injections along with a diet at his own weight-loss clinics.

HCG Diet Protocol

The HCG diet is usually administered in either a 23-day or 40-day protocol under the supervision of a licensed physician. After a thorough, general medical exam and a week-long, detoxing pre-diet, a patient either receives daily injections or self-administers them every day for the desired protocol length. (Sublingual drops may also be taken.) The patient also follows a strict, extremely low-calorie diet through the end of the program, and then a higher-calorie maintenance diet afterwards.

HCG in the Bloodstream

Towards the end of a 40-day protocol, patients may begin to develop an immunity to the effect of HCG because so much of the substance has built up in their systems. After this, the patient should stop the protocol, but still follow a relatively low-calorie maintenance diet for at least three weeks. After six weeks, the HCG will have finally run out of the patient's system, and a new protocol can be started. However, the shots themselves last approximately three days each. For this reason patients must continue to follow the low-calorie diet for three days after the last injection.

Considerations

Like any other supplement or medication, HCG does cause some side effects. Headaches and weakness are often common during the first few days of the protocol, as are intestinal troubles like constipation and diarrhea. Further, while HCG itself is FDA-approved, it is not FDA-approved as a weight-loss supplement, and weight-loss clinics that administer it for this purpose must disclose that. Most studies have not shown the HCG itself to cause weight loss, which is attributed in these cases instead to the low-calorie diet. If you choose to follow an HCG diet protocol, do so under the supervision of a trusted physician.