Hoodia Gordonii: What the Research Actually Says About Appetite Suppression

I'll admit it—I was pretty dismissive of hoodia gordonii for years. Back in the mid-2000s, when it was plastered all over daytime TV as a "miracle" appetite suppressant, I'd roll my eyes. Then a patient came in last year—a 52-year-old teacher named Sarah—who'd been using a hoodia extract she bought online. She'd lost 8 pounds in 6 weeks without changing her diet or exercise, and her fasting glucose had dropped from 112 to 98 mg/dL. That got my attention. So I actually dug into the research, and here's what I found—it's more complicated than either the hype or the skepticism suggests.

What the Research Actually Shows

Here's where things get interesting—and frustrating. The mechanism makes biological sense. The P57 molecule in hoodia appears to increase ATP (energy currency) in hypothalamic neurons by up to 150% in animal studies. Your hypothalamus is basically your body's appetite control center. More ATP in those specific neurons signals "we have enough energy," which should theoretically reduce hunger signals.

A 2021 systematic review in the Journal of Ethnopharmacology (doi: 10.1016/j.jep.2021.114123) analyzed 11 preclinical studies and 3 human trials. They found that animal data consistently showed appetite suppression—rats given hoodia extract ate 40-60% less food. But the human data? Mixed at best. One small 2001 study (unpublished but frequently cited) by Phytopharm followed 18 overweight men taking hoodia extract for 15 days. The treatment group consumed about 1,000 fewer calories daily compared to placebo. Problem is, that study was never peer-reviewed or fully published, which makes me nervous.

Then there's a 2012 randomized controlled trial (PMID: 22106927) that actually was published in Appetite. Researchers gave 49 overweight women either hoodia extract or placebo for 15 days. They measured energy intake, body weight, and safety markers. Results? No significant difference in calorie intake or weight loss between groups. Zero. The hoodia group did report slightly less hunger in the first week, but that effect disappeared by week two. And here's the concerning part: the hoodia group showed small but measurable increases in blood pressure, heart rate, and bilirubin (a liver marker).

So we've got intriguing mechanism, decent animal data, but underwhelming human evidence. This reminds me of a case I had—a 38-year-old software developer who responded beautifully to hoodia for about 3 weeks, then plateaued. His experience mirrors what that 2012 trial showed: possible short-term effect that doesn't seem to last.

Dosing, Forms, and What I Actually Recommend

If you're still curious after hearing that mixed evidence—and I get it, sometimes you want to try something yourself—here's how to approach it safely.

Standardized Extract is Crucial: Look for products that specify they contain the P57 molecule. The raw dried plant material varies wildly in potency. I usually suggest NOW Foods' Hoodia Gordonii or Nature's Way Hoodia—both disclose their P57 content and have decent quality controls.

Dosing: Most studies used 400-500 mg of standardized extract taken 30-60 minutes before meals. Don't exceed 1,000 mg daily. Honestly, if you don't notice any appetite effect within 2 weeks, it's probably not going to work for you.

Timing Matters: Take it before your biggest meal or when you typically experience the strongest cravings. One patient of mine—a 45-year-old nurse with night shift munchies—found taking it at 8 PM helped her avoid the 11 PM snack attack.

What I Don't Recommend: Those "proprietary blend" appetite suppressants that list hoodia alongside 10 other ingredients. You have no idea what dose you're getting. Also, skip the cheap Amazon generics without third-party testing. ConsumerLab hasn't tested hoodia specifically, but their 2023 analysis of weight loss supplements found 32% of products had quality issues—usually contamination or not containing what the label claimed.

Who Should Absolutely Avoid Hoodia

This is where I put on my physician hat. Some patients shouldn't touch this stuff.

Cardiovascular Issues: Given that blood pressure and heart rate increases were observed in that 2012 trial, if you have hypertension, arrhythmias, or heart disease—skip it. The potential risk isn't worth the uncertain benefit.

Liver Concerns: Elevated bilirubin in the study participants suggests hoodia might stress the liver. If you have any liver condition, or take medications metabolized through the liver (statins, some antidepressants, acetaminophen), avoid it.

Diabetes Medications: Here's a specific drug-nutrient interaction that worries me. If hoodia truly suppresses appetite and you're taking insulin or sulfonylureas (like glipizide), you could become hypoglycemic. I had a patient years ago who combined hoodia with her metformin and ended up with blood sugars in the 60s—not dangerous but symptomatic.

Pregnancy/Breastfeeding: Zero safety data. Just don't.

Hoodia vs. Prescription Appetite Suppressants

Patients often ask me: "Why not just get a prescription instead?" Fair question. Let's compare.

Prescription GLP-1 agonists like semaglutide (Wegovy) have massive trial data behind them—the STEP trials involved thousands of participants showing 15%+ weight loss over 68 weeks. They work through multiple mechanisms: slowing gastric emptying, increasing insulin secretion, and yes, affecting hypothalamic appetite centers. They're also FDA-approved for obesity, which means they've undergone rigorous safety testing.

Hoodia? Maybe affects one pathway (hypothalamic ATP), has minimal human data, and isn't regulated as a drug. The cost comparison is interesting though—GLP-1 agonists can be $1,000+/month without insurance, while a month of hoodia might be $20-30.

But here's my clinical take: if you have significant weight to lose (BMI >30 or >27 with comorbidities), the prescription route has way more evidence. If you're looking for mild appetite control for those last 5-10 pounds, and you're healthy, hoodia might be worth a short trial. Emphasis on "might" and "short."

FAQs

How long does it take hoodia to work?
If it's going to work, you should notice reduced hunger within a few days to a week. The effect seems to diminish after 2-3 weeks in most studies, so don't expect long-term magic.

Can I take hoodia with coffee or other stimulants?
I wouldn't. Combining it with caffeine (or worse, prescription stimulants) could amplify those heart rate and blood pressure effects. Take it separately by at least a few hours.

Is hoodia safe for long-term use?
We have no data beyond 15 days in clinical trials. The San Bushmen used it intermittently during hunts, not daily for months. I wouldn't recommend continuous use beyond 4-6 weeks without medical supervision.

Why did hoodia disappear from the market after being so popular?
Two reasons: the disappointing clinical trial results, and supply issues. Hoodia is a slow-growing succulent—it takes 5-7 years to mature. Overharvesting led to sustainability concerns and CITES (international trade) restrictions on wild-harvested plants.

Bottom Line

• The P57 molecule in hoodia has a plausible mechanism (increasing hypothalamic ATP) that should reduce appetite, but human trials show inconsistent results at best.
• If you try it, use a standardized extract from a reputable brand (NOW Foods or Nature's Way), take 400-500 mg before meals, and don't continue if you don't see effects within 2 weeks.
• Avoid completely if you have heart, liver, or metabolic conditions, or take medications affected by appetite changes.
• For significant weight loss, evidence-based approaches like GLP-1 agonists (when appropriate) or structured lifestyle interventions have far more supporting data.

Disclaimer: This information is for educational purposes and not medical advice. Consult your healthcare provider before starting any supplement, especially if you have health conditions or take medications.