Clinical Context
The global obesity epidemic affects over 650 million adults worldwide, driving demand for effective and safe weight management interventions. While lifestyle modification remains foundational, many patients struggle to achieve meaningful weight loss through diet and exercise alone. Pharmacological options are limited by side effects, contraindications, or insufficient efficacy, creating interest in natural product supplements that might augment lifestyle interventions.
Cyperus rotundus (nutgrass or purple nutsedge) has been used in traditional medicine systems including Ayurveda for various conditions. The rhizome contains stilbene compounds with documented antioxidant, anti-inflammatory, and metabolic effects in preclinical studies. These phytochemicals may influence lipid metabolism, adipogenesis, and metabolic rate through multiple mechanisms.
Piperine, derived from black pepper, is commonly combined with herbal supplements to enhance bioavailability by inhibiting drug-metabolizing enzymes and increasing intestinal absorption. This combination approach (CREP: Cyperus rotundus extract with piperine) aims to maximize the therapeutic potential of the plant extract through improved systemic delivery.
PICO Summary
Population: 96 obese adults enrolled in a 90-day randomized, double-blind, placebo-controlled clinical trial.
Intervention: Oral supplementation of 500 mg Cyperus rotundus extract (standardized to 6-8% stilbenes) with 5 mg piperine (CREP), taken twice daily in addition to a prescribed diet and exercise regimen.
Comparison: Matching placebo administered twice daily with identical diet and exercise guidance.
Outcome: CREP supplementation significantly reduced body weight, BMI, waist circumference, and hip circumference compared to placebo. Lipid profiles improved with reduced triglycerides and LDL-cholesterol, increased HDL-cholesterol, and lowered Apolipoprotein B-100. No adverse events or laboratory abnormalities were reported.
Clinical Pearls
1. Additive to Lifestyle, Not Replacement: Both groups received diet and exercise guidance; CREP provided additional benefit beyond lifestyle modification alone. This is the appropriate use case for supplements—augmenting rather than replacing foundational interventions.
2. Lipid Benefits Independent of Weight: The improved lipid profiles (reduced TG, LDL, ApoB-100; increased HDL) suggest metabolic benefits that may exceed what weight loss alone would explain. Stilbene compounds may have direct effects on lipid metabolism similar to resveratrol.
3. Waist and Hip Circumference Reduced: The decreases in waist and hip measurements suggest reduction in visceral and subcutaneous fat depots, not just overall weight. Central adiposity reduction is particularly valuable given its association with cardiometabolic risk.
4. Safety Profile Favorable Over 90 Days: The absence of adverse events and normal laboratory parameters throughout the trial supports short-term safety. However, longer-term safety data would be needed to recommend extended use.
Practical Application
CREP supplementation may be considered for obese patients seeking natural product adjuncts to lifestyle modification who have no contraindications to herbal supplements. Ensure patients understand this is supportive therapy; continued diet and exercise adherence remains essential for meaningful results.
The dosing protocol (500 mg extract + 5 mg piperine twice daily) should be followed as studied. Commercial preparations vary in standardization; products with verified stilbene content (6-8%) are preferred. Quality control and third-party testing for herbal supplements varies widely by manufacturer.
Note that piperine can affect drug metabolism and may interact with medications metabolized by cytochrome P450 enzymes. Review medication lists before recommending CREP, and advise caution in patients on narrow-therapeutic-index drugs.
Broader Evidence Context
This trial adds to limited clinical evidence for Cyperus rotundus in metabolic disease. Preclinical studies have demonstrated anti-obesity, antidiabetic, and lipid-lowering effects, but human trials have been sparse. The stilbene compounds in C. rotundus share structural similarities with resveratrol, which has more extensive metabolic research.
The herbal supplement market lacks the regulatory rigor of pharmaceutical development. While this trial provides encouraging efficacy data, replication by independent investigators and larger sample sizes would strengthen confidence. Quality control concerns with commercial preparations remain relevant.
Study Limitations
The 90-day duration doesn’t establish long-term efficacy or safety. The relatively small sample size (96 participants) limits detection of rare adverse events. Adherence to diet and exercise components wasn’t objectively verified. The specific CREP formulation may not be widely available or consistent across manufacturers.
Bottom Line
Cyperus rotundus extract with piperine supplementation produces significant reductions in body weight, body composition measures, and lipid parameters compared to placebo when combined with diet and exercise over 90 days. For patients seeking natural product adjuncts to lifestyle modification, CREP represents a potentially effective and well-tolerated option.
Source: Majeed A, et al. “Efficacy and Safety of Cyperus rotundus Extract on Weight Management in Obese Individuals: A Randomized, Double-Blind, Placebo-Controlled Study.” 2025. Read article
