HCG Diet for Weight Loss: Not Recommended
The HCG diet should not be used for weight loss—it is ineffective and potentially dangerous, with no scientific evidence supporting its efficacy and documented risks including thromboembolism. 1, 2, 3
Evidence Against HCG Diet Efficacy
The HCG diet, originally described by Simeons in 1954, combines daily injections of human chorionic gonadotropin (125 IU intramuscularly) with severe caloric restriction (500 kcal/day). 4 Despite over half a century of use, the scientific evidence consistently refutes its effectiveness:
Multiple double-blind, placebo-controlled trials demonstrate no advantage of HCG over placebo for weight loss, body composition changes, hunger suppression, or body proportion normalization. 4, 2
A rigorous 6-week double-blind study of 40 obese women (BMI >30 kg/m²) receiving either HCG or saline injections with identical 5,000 kJ/day diets showed no differences in weight loss, hunger levels, body circumferences, or any measured variables between groups. 2
Systematic review of the literature identified 10 studies showing positive results (mostly uncontrolled case reports) versus 10 studies showing negative results (including 6 double-blind controlled trials)—all well-designed studies refute HCG efficacy. 4
Any weight loss observed is attributable entirely to the severe caloric restriction (500-800 kcal/day), not the HCG hormone. 1, 2
Safety Concerns and Documented Risks
Beyond lack of efficacy, the HCG diet poses significant health risks:
Documented case of bilateral pulmonary embolisms and deep vein thrombosis in a 64-year-old woman who started the HCG diet (20 sublingual drops twice daily) two weeks prior, with no other identifiable risk factors and negative hypercoagulable workup (Naranjo probability scale: probable causation). 3
The severe caloric restriction component (<800 kcal/day) requires close medical supervision due to rapid weight loss and potential complications, yet HCG diet products are marketed directly to consumers without medical oversight. 5, 3
Currently marketed HCG products (sublingual drops, lozenges, pellets) have no evidence-based efficacy or safety standards, and their actual contents may differ from labeling. 1, 3
Evidence-Based Alternatives for Weight Loss
Instead of the HCG diet, established guidelines recommend proven approaches:
Calorie-Restricted Diets
- Prescribe 1,200-1,500 kcal/day for women and 1,500-1,800 kcal/day for men, or create a 500-750 kcal/day energy deficit from baseline. 5
- Very-low-calorie diets (<800 kcal/day) should only be used in limited circumstances under direct medical supervision with high-intensity lifestyle intervention, not as self-directed programs. 5
Comprehensive Lifestyle Intervention
- Recommend participation in programs lasting ≥6 months that combine dietary counseling, increased physical activity, and behavioral strategies delivered through ≥14 sessions by trained interventionists. 5
- Weight loss of 5% of initial body weight improves metabolic and reproductive abnormalities in conditions like PCOS and obesity-related comorbidities. 5
Macronutrient-Based Approaches
- Low-carbohydrate, low-fat, Mediterranean, DASH, and vegetarian dietary patterns all produce similar weight loss when combined with energy restriction—adherence predicts success more than specific macronutrient composition. 5, 6
- In the short term, high-protein low-carbohydrate diets may produce greater initial weight loss but long-term outcomes are equivalent to other approaches. 5, 6
Clinical Bottom Line
The HCG diet represents an unfounded and potentially harmful weight loss strategy that persists despite consistent scientific refutation over 60+ years. 1, 4 Any weight loss achieved results entirely from dangerous caloric restriction, not the hormone, while exposing patients to thrombotic risks and other complications without medical supervision. 2, 3 Clinicians should actively discourage patients from pursuing this diet and instead recommend evidence-based approaches including moderate caloric restriction (1,200-1,800 kcal/day depending on sex), comprehensive lifestyle programs with behavioral support, and dietary patterns that patients can sustain long-term. 5, 6