What is Hoodia?
Hoodia (Hoodia gordonii) is a cactus-like succulent plant native to the Kalahari Desert of southern Africa, primarily in South Africa, Namibia, and Botswana. Despite its cactus-like appearance, it actually belongs to the milkweed family (Apocynaceae). For thousands of years, the indigenous San (Khoi-San or "Bushmen") people of the Kalahari have chewed the bitter, fleshy stems of Hoodia during long hunting expeditions to suppress hunger and thirst across the harsh desert landscape. This traditional use sparked global interest in the late 1990s and early 2000s, when Hoodia was heavily marketed as a "miracle" appetite suppressant for weight loss.
Today, Hoodia is one of the more controversial ingredients in the supplement world. While its traditional use is well-documented and a single active compound (P57) has been identified and patented, the modern clinical evidence for its effectiveness in humans is weak, and concerning safety signals have emerged in the limited research available. Additionally, Hoodia gordonii is now listed as an endangered species under CITES (Convention on International Trade in Endangered Species), raising serious sustainability and authenticity concerns in the commercial supplement market.
Common Names: Hoodia, Hoodia gordonii, Bushman's Hat, Xhoba, Queen of the Namib, Ghaap
Primary Active Compounds:
P57 (P57AS3): An oxypregnane steroidal glycoside identified as the primary appetite-suppressing compound; isolated and patented by the South African Council for Scientific and Industrial Research (CSIR) in 1996
Hoodigogenin A: A steroidal aglycone that serves as the backbone for many of Hoodia's active glycosides
Hoodigosides: A family of steroidal glycosides unique to Hoodia species
Hoodistanalosides: Additional steroidal glycoside compounds
Gordonosides: Steroidal glycoside derivatives, including gordonoside F
Calogenin glycosides: Steroidal compounds contributing to the plant's chemistry
Pregnane glycosides: Broader family of compounds with potential appetite-suppressing activity
Various trace flavonoids and minor steroidal constituents
Key Note: P57 is present in only minute amounts in the raw plant material. Many commercial supplements marketed as "Hoodia" have been shown through independent laboratory testing to contain very little or no authentic Hoodia gordonii, or to lack sufficient P57 to produce any physiological effect. This is the single most important quality issue with this ingredient.
Primary Functions & Benefits
Appetite Suppression (Traditional Use):
Traditionally used by San people to suppress hunger during multi-day hunting expeditions
May reduce the urge to eat by signaling satiety through the hypothalamus
May reduce calorie intake when combined with diet and exercise
Reduces sensation of hunger between meals in some users
Theorized Weight Loss Support:
May contribute to caloric deficit by reducing food intake
Marketed as an adjunct to weight management programs
Potentially helpful for emotional or stress-induced overeating (anecdotal)
May reduce snacking and grazing behavior
Thirst Suppression (Traditional Use):
Historically chewed by indigenous hunters to suppress thirst in arid conditions
Mechanism is not well understood; this benefit has received almost no modern research
Potential Metabolic Effects (Animal Studies Only):
Animal studies suggest increased liver glycogen stores
Increased thyroid hormone activity in rats
Decreased neuropeptide Y (NPY), an appetite-stimulating hormone
Marginal increases in leptin and cholecystokinin (satiety hormones) in rats
Increased mitochondrial CPT-1 activity (fat metabolism enzyme) in rats
Important Honest Assessment:
The "benefits" of Hoodia are primarily theoretical and based on traditional use, animal studies, and laboratory research. The single best-quality human clinical trial showed NO weight loss benefit and significant adverse effects. Consumers should approach Hoodia with realistic expectations and a clear understanding that the marketing claims significantly exceed the scientific evidence.
Recommended Dosages
Important Disclaimer:
There is no established safe or effective dose of Hoodia for humans based on rigorous clinical research. The doses listed below are commonly used in commercial products and traditional practice, but should be approached with caution.
Standardized Extract (Capsules/Tablets):
Common commercial dose: 400-1,200 mg of Hoodia gordonii extract daily
Pre-meal dosing: 400-500 mg taken 30-60 minutes before main meals, 1-3 times daily
Clinical trial dose: 1,110 mg of purified Hoodia gordonii extract twice daily was used in the 2011 Blom et al. randomized trial; this trial showed adverse effects without weight loss benefit
Maximum daily intake: Generally not exceeding 3,000 mg, though this is anecdotal rather than research-based
Raw Powder:
Typical range: 500-1,000 mg per serving, taken before meals
Traditional preparation: San hunters would chew chunks of fresh stem; modern equivalence is difficult to establish
Liquid Extracts/Tinctures:
Typical range: 1-2 mL (approximately 30-60 drops) taken 30 minutes before meals
Concentration and quality vary dramatically between products
Duration:
No clear safety data for long-term use exists
Most products recommend cycling: 4-8 weeks of use followed by a break
Long-term effects beyond a few weeks are essentially unstudied in humans
Quality Disclaimer:
Independent laboratory analyses have repeatedly found that many commercial Hoodia products contain little or no authentic Hoodia gordonii, or contain insufficient P57 to produce any effect. Even at the recommended doses, the actual amount of active compound delivered may be negligible in many products. Choose only products with CITES certification of origin and third-party verification of authenticity.
Timing & Administration
Best Time to Take:
For appetite suppression: 30-60 minutes before main meals (breakfast, lunch, and/or dinner)
For snack control: Between meals when hunger cravings typically occur
Pre-workout meals: Avoid taking immediately before exercise due to potential cardiovascular effects (elevated heart rate, blood pressure)
Evening doses: Consider avoiding late-evening dosing if it affects sleep or causes restlessness
With or Without Food:
Capsules and tablets: Take on an empty stomach with water, ideally 30-60 minutes before eating, for the theoretical appetite-suppressing effect to take hold before mealtime
Liquid extracts: Same approach; taking with water on an empty stomach
If GI upset occurs: Switch to taking with a small amount of food, accepting that this may reduce effectiveness
Absorption Notes:
The intestinal transport of P57 is mediated by P-glycoprotein (P-gp) and MRP transporters, which actively pump it back out of cells
This efflux mechanism means absorption of P57 is naturally limited
One study found P57 was undetectable in the brain of mice after oral administration, raising questions about whether oral Hoodia can reach the hypothalamus where it is theorized to act
This is one of the major scientific challenges to Hoodia's purported mechanism
Onset of Effects:
Appetite suppression (if it occurs): Reported within 30-60 minutes after consumption
Anecdotal users often report effects within the first few days; placebo response is significant with this ingredient
Animal studies show appetite suppression effects lasting approximately 6 hours, with food intake restored within 24 hours after stopping
In the major human clinical trial, no objective changes in caloric intake or body weight occurred after 15 days of daily use
What to Expect:
Hoodia is not a thermogenic stimulant; it should not produce the "wired" feeling of caffeine-based supplements
However, the major human trial showed it does raise heart rate and blood pressure, suggesting some sympathomimetic activity
Effects vary significantly between individuals and between products of different quality
Realistic expectations are essential; this is not a guaranteed weight loss tool
How Hoodia Works
Proposed Mechanisms of Action:
Hypothalamic ATP elevation (theorized): P57 is proposed to increase ATP concentrations in hypothalamic neurons, which the brain interprets as a "fed" state, reducing appetite signals; this mechanism was demonstrated only when P57 was injected directly into the brain of rats, not after oral administration
Mimicking glucose satiety: Glucose normally raises ATP and signals fullness; P57 may mimic this signal without providing actual calories
Sympathomimetic activity: Recent research suggests Hoodia may stimulate beta-adrenergic receptors, which can reduce appetite but also explains its cardiovascular side effects (increased heart rate and blood pressure)
Modulation of appetite hormones (animal studies): Decreased NPY (neuropeptide Y, an appetite stimulator) and marginal increases in leptin and CCK (satiety hormones)
Thyroid hormone elevation (animal studies): May slightly increase metabolic rate through thyroid activity
Liver glycogen modulation: Increased glycogen storage in animal studies, which may contribute to a "fed" metabolic state
Mechanistic Concerns:
The leading P57 mechanism has not been reliably replicated in humans
Oral P57 may not cross the blood-brain barrier in sufficient quantities to act on the hypothalamus
The sympathomimetic activity (heart rate and blood pressure elevation) is a likely explanation for some appetite suppression but is also a safety concern
Multiple other compounds in Hoodia may be responsible for effects beyond P57
The full chemical composition and mechanisms of Hoodia remain incompletely characterized
Synergistic Supplements
Important Note:
Because Hoodia's effectiveness and safety are both questionable, "stacking" it with other supplements should be done with extra caution. The following combinations are commonly used in commercial products, but their combined effects and safety are not well studied.
Commonly Combined With (Use Cautiously):
Green tea extract (EGCG): For metabolic and thermogenic support; combined cardiovascular load is a concern
Chromium picolinate: For blood sugar regulation and reduced cravings
Fiber supplements (glucomannan, psyllium): Adds physical satiety to complement appetite suppression
L-Carnitine: For fat metabolism support
CLA (Conjugated Linoleic Acid): For body composition support
B-complex vitamins: For energy metabolism support during caloric restriction
5-HTP: For appetite control through serotonin pathways (do NOT combine with antidepressants)
Beneficial Lifestyle Pairings:
Increased water intake (counteracts traditional thirst-suppressing effect, important for safety)
High-protein meals (independent satiety support)
Adequate sleep (regulates hunger hormones)
Stress management practices (reduces emotional eating)
Regular physical activity (within tolerance, given potential cardiovascular effects)
Avoid Stacking With:
Other stimulants (caffeine in high doses, synephrine, ephedra-like compounds)
Other appetite suppressants with cardiovascular effects
Multiple weight loss supplements simultaneously
Interactions & What NOT to Take
Significant Concerns:
Diabetes medications (Insulin, Metformin, Sulfonylureas): Hoodia may affect blood sugar regulation; combination may cause hypoglycemia or unpredictable glucose levels
Heart medications and antihypertensives: Hoodia has been shown to increase blood pressure and heart rate, potentially counteracting cardiovascular drugs or causing dangerous interactions
Beta-blockers: Hoodia's apparent sympathomimetic activity may oppose the effects of beta-blockers
Blood thinners (Warfarin, Aspirin, Heparin): Theoretical bleeding risk; insufficient data on direct interactions
CYP3A4 substrates: P57 weakly inhibits CYP3A4 (IC50 of 45 microM); may modestly affect metabolism of many common drugs
Stimulant medications (ADHD medications, decongestants): Additive cardiovascular effects (elevated heart rate, blood pressure)
Antidepressants (especially MAOIs, SNRIs): Theoretical concerns due to potential sympathomimetic activity
Thyroid medications: Hoodia may affect thyroid hormone levels (animal studies); could interfere with thyroid medication dosing
Avoid Combining With:
Ephedra or ephedra-like compounds (banned in many countries due to cardiovascular risks)
Bitter orange (synephrine) in significant doses
High-dose caffeine or pre-workout supplements with multiple stimulants
Other appetite suppressant medications (phentermine, topiramate, etc.)
Energy drinks with stimulant blends
Substances That May Increase Hoodia's Risks:
Alcohol (additional cardiovascular and liver stress)
Recreational stimulants (cocaine, amphetamines; all forms)
Other unregulated weight loss supplements (compounded risks and unknown interactions)
Who Should Take Hoodia
Honest Assessment:
Given the weak evidence for effectiveness and notable safety concerns, Hoodia is generally not a strongly recommended supplement for most people. The following describes who might consider it, with appropriate caution.
Possible Candidates:
Healthy adults with no cardiovascular conditions who want to experiment with traditional appetite suppressants
Individuals who have tried conventional approaches (diet, exercise, fiber supplementation, behavioral changes) without success
People committed to a comprehensive weight management plan who are seeking adjunctive support
Those who can purchase verified, authentic, CITES-certified Hoodia products
Adults willing to start with low doses and monitor for adverse effects
Individuals with no significant comorbidities or medication use
Better Alternatives to Consider First:
Soluble fiber supplements (glucomannan, psyllium) for satiety
High-protein dietary approaches
Mindful eating and behavioral strategies
Established weight loss approaches (Mediterranean diet, time-restricted eating)
For those needing medication-level support: consultation with a physician about GLP-1 agonists or other prescription options
Who Should AVOID or Use Caution
Contraindications (Should NOT Take):
People with heart disease, arrhythmias, or cardiovascular conditions: Hoodia raises heart rate and blood pressure
Individuals with hypertension (high blood pressure): Documented blood pressure elevation
People with diabetes or blood sugar disorders: May interfere with glucose regulation
Individuals with liver disease: Reports of elevated bilirubin and alkaline phosphatase
People with bleeding disorders or on blood thinners: Theoretical concerns
Pregnant women: No safety data; traditional use does not cover pregnancy; potentially harmful effects unknown
Breastfeeding women: No safety data; should not be used
Children and adolescents: No safety or efficacy data in pediatric populations
People with eating disorders (anorexia, bulimia): Appetite suppressants are inappropriate and dangerous in this population
Individuals with thyroid disorders: Potential to affect thyroid hormone levels
People with kidney disease: Limited safety data and potential for fluid balance issues
Use Caution:
Anyone with mental health conditions, particularly anxiety disorders
Individuals sensitive to stimulant-like compounds
Those taking multiple medications
Older adults (limited safety data in this population)
People scheduled for surgery (discontinue at least 2 weeks before due to cardiovascular and bleeding concerns)
Anyone who notices increased heart rate, palpitations, or blood pressure changes after starting
Quality and Sourcing Concerns:
Avoid Hoodia products without CITES certification, since the plant is endangered
Avoid products without third-party authentication testing
Be skeptical of inexpensive Hoodia products, as authentic Hoodia is rare and costly
Avoid products with proprietary blends that hide actual Hoodia content
Benefits of Taking Hoodia
Honestly Assessed Benefits:
Traditional appetite suppression: Centuries of use by the San people provides some real-world evidence, though context (extreme exertion and dehydration) was very different from modern usage
Possible reduced caloric intake: Animal studies show 12-26% reductions in food intake at certain doses
Psychological/placebo benefit: For some users, the act of taking an appetite suppressant before meals may support mindful eating and portion control
Potential niche use: May be helpful for some individuals as part of a comprehensive weight management strategy
Cultural and ethnobotanical interest: Provides connection to traditional plant medicine knowledge
Benefits NOT Strongly Supported by Evidence:
Significant weight loss: The major human clinical trial showed no weight loss benefit
Long-term weight maintenance: No evidence supports this
Metabolic enhancement: Animal studies suggest minor effects, but human translation is unclear
Cardiovascular protection or other "health" benefits: No evidence; actually shows opposite cardiovascular effects
"Fat burning": Hoodia is not a thermogenic and does not directly burn fat
Most Honest Statement:
Hoodia may produce modest appetite suppression in some individuals through poorly understood mechanisms, but it has not been proven to produce meaningful weight loss in rigorous clinical trials. Its benefits are likely modest at best and may be outweighed by safety concerns for many people.
Potential Negatives & Side Effects
Documented Side Effects (from clinical research and consumer reports):
Nausea: Reported frequently in the major clinical trial
Vomiting: Reported in clinical research
Dizziness: Commonly reported by consumers
Skin sensations: Abnormal skin sensitivity, tingling, or unusual feelings reported in the clinical trial
Elevated heart rate (tachycardia): Documented in human studies
Elevated blood pressure: Documented in human studies; clinically significant
Headaches: Commonly reported
Anxiety or restlessness: Reported by some users
Insomnia: Reported, particularly with evening doses
Liver-Related Concerns:
Elevated bilirubin: Documented in the major human trial
Elevated alkaline phosphatase: Documented in the major human trial
ALT (alanine aminotransferase) did not increase in the trial, so clinically significant liver injury was not confirmed
The LiverTox database indicates no confirmed cases of clinically apparent liver injury, but the abnormal liver markers warrant attention
Lesser Documented but Reported:
Loss of taste
Strange dreams
Dry mouth
Decreased mental clarity (paradoxical, since proposed mechanism is hypothalamic ATP elevation)
Reduced thirst (which can be dangerous, as it may lead to dehydration)
Constipation (from reduced food intake)
Quality & Authenticity Concerns:
Independent testing has repeatedly found commercial Hoodia products contain little or no authentic Hoodia
Some products have been adulterated with pharmaceutical weight loss drugs (sibutramine, others) without disclosure
Counterfeit products may cause unexpected side effects from undisclosed ingredients
Even authentic products vary greatly in P57 content
The supplement is sold widely without pre-market safety testing in most countries
Sustainability/Ethical Concerns:
Hoodia gordonii is listed under CITES Appendix II (endangered/threatened species)
Wild populations have been severely depleted by overharvesting
Authentic Hoodia requires special permits for cultivation and export
Purchasing non-certified Hoodia may contribute to illegal harvesting and species decline
Deficiency Symptoms
Note: Hoodia is not a nutrient or essential compound, so there is no such thing as a Hoodia "deficiency." There are no symptoms that indicate a need for Hoodia supplementation specifically.
Conditions Some People Use Hoodia to Address:
Difficulty controlling portion sizes during meals
Frequent snacking or grazing behavior
Hunger between meals
Stress eating or emotional eating
Excess appetite from medication side effects
Slow weight loss progress despite diet and exercise
Signs That Are Better Addressed Through Other Means:
Constant hunger may indicate inadequate protein intake, blood sugar dysregulation, or poor sleep
Cravings may indicate nutrient deficiencies, dehydration, or emotional needs
Difficulty losing weight may benefit from professional guidance rather than appetite suppressants
Persistent overeating may benefit from behavioral therapy or medical consultation
For most appetite and weight management concerns, evidence-based dietary, behavioral, and lifestyle interventions are more effective and safer than Hoodia supplementation.
Toxicity Symptoms
Acute Overdose/Toxicity:
Severe nausea and vomiting
Significantly elevated blood pressure (hypertensive episode)
Rapid heart rate or palpitations
Severe dizziness or fainting
Chest pain or pressure
Cardiac arrhythmias
Severe headache
Confusion or altered mental status
Long-term Toxicity Concerns:
Long-term safety data does not exist for Hoodia in humans
Sustained elevations in heart rate and blood pressure could contribute to cardiovascular damage over time
Liver enzyme abnormalities suggest potential for hepatic stress with prolonged use
Cumulative effects on appetite regulation hormones are unknown
Potential for nutritional deficiency if appetite suppression leads to inadequate food intake
Signs of Serious Adverse Reaction (Seek Medical Attention):
Chest pain, pressure, or tightness
Severe shortness of breath
Irregular or pounding heartbeat
Signs of stroke (one-sided weakness, slurred speech, facial drooping)
Severe abdominal pain
Yellowing of skin or eyes (jaundice; possible liver involvement)
Dark urine or pale stools (possible liver involvement)
Severe allergic reactions (swelling, difficulty breathing)
Persistent vomiting causing dehydration
Adulteration-Related Toxicity:
Symptoms not consistent with traditional Hoodia effects may indicate product adulteration
Sibutramine contamination has been found in some Hoodia products (this drug was withdrawn from many markets due to cardiovascular risks)
Other undisclosed stimulants may be present
If experiencing severe or unusual reactions, stop the product immediately and report it to relevant authorities (FDA MedWatch in the US)
Special Considerations
Form Selection:
Capsules and tablets: Most common form; quality varies dramatically; look for CITES certification and third-party testing
Powdered extract: Allows for dose adjustment but may have variable potency; bitter taste limits palatability
Liquid extracts (tinctures): Less common; concentration varies; allows for flexible dosing
Whole stems (raw or dried): Most traditional form; rarely available legally outside Africa due to CITES restrictions; extremely bitter
"Hoodia patches": These transdermal patches have no scientific support and are generally considered fraudulent products
Quality Indicators:
CITES certification: Essential for authenticity and legal sourcing
South African origin documentation: The species is endemic to southern Africa
Third-party testing for P57 content: Most reliable products will publish or provide testing results
Reputable manufacturers: Major brands with GMP (Good Manufacturing Practices) certification
Authentication via DNA testing or chromatographic methods: The gold standard for verifying authenticity
Sustainable cultivation claims: Wild-harvested Hoodia is concerning; cultivated sources are preferred
Sustainability Awareness:
Hoodia gordonii is protected under CITES Appendix II as a threatened species
Wild populations have been depleted by years of overharvesting fueled by Western weight loss demand
Ethical sourcing requires either certified cultivated Hoodia or wild-harvested material with proper CITES permits
The San people of southern Africa have established a benefit-sharing agreement (2003) to receive royalties from commercial Hoodia products; supporting authenticated products with this provenance supports the indigenous community
Realistic Expectations:
Hoodia is not a "miracle" weight loss solution despite past marketing claims
Effects, if any, are typically modest
Hoodia works best (if at all) as one component of a comprehensive weight management approach
Significant weight loss requires sustained dietary and lifestyle changes
Individual response varies dramatically; some people may notice nothing, others may experience side effects without benefits
Why Sustainable Alternatives May Be Better:
Given the safety concerns, weak evidence, sustainability issues, and authenticity problems, many health professionals recommend alternative appetite management strategies:
High-fiber foods and fiber supplements (glucomannan)
Adequate protein intake at each meal
Mindful eating practices
Behavioral approaches to eating
Medical consultation for prescription options when appropriate
Research Status & Evidence Quality
Strong Evidence For:
Traditional ethnobotanical use by San people for appetite and thirst suppression
Presence of unique steroidal glycosides (P57 and related compounds)
Adverse effects including elevated blood pressure and heart rate in human studies
Significant adulteration problems in the commercial supplement market
Moderate Evidence For:
Animal studies showing appetite reduction at specific doses
Theorized hypothalamic ATP elevation mechanism (demonstrated only with direct brain injection in animals)
Modulation of appetite-regulating hormones in animal models
Sympathomimetic activity contributing to both effects and side effects
Weak or No Evidence For:
Meaningful weight loss in humans (the major human trial showed NO weight loss benefit)
Long-term safety and efficacy
Effectiveness of commercially available Hoodia supplements at typical doses
Bioavailability of oral P57 reaching the brain in sufficient concentrations
Clinical superiority over placebo for sustained appetite suppression
Research Limitations:
Only one major peer-reviewed randomized controlled trial of purified Hoodia extract has been published (Blom et al. 2011)
That trial showed no efficacy and significant adverse effects
The European Food Safety Authority (EFSA) declined to authorize Hoodia for safety in 2010
Most research has been preclinical (animal or laboratory studies)
Industry-funded studies have shown more favorable results than independent research
The full chemical composition of Hoodia and mechanisms of action remain incompletely characterized
Regulatory Status:
The United States FDA has not approved Hoodia for any medical indication
The EU has not granted safety authorization
Available as a dietary supplement without pre-market safety testing in many countries
CITES protection limits legal trade in the raw plant
Summary & Key Takeaways
Hoodia (Hoodia gordonii) is a traditional appetite suppressant from southern Africa with a fascinating history and patented active compound (P57), but the modern clinical evidence does not support its effectiveness for weight loss in humans. The single best-quality human clinical trial showed no weight loss benefit while documenting concerning side effects including elevated blood pressure, increased heart rate, nausea, vomiting, and skin sensations. Additionally, Hoodia is an endangered species protected under CITES, and the commercial supplement market suffers from significant adulteration, mislabeling, and counterfeiting problems.
Bottom Line: Hoodia is a supplement with limited scientific support for its primary marketing claim (weight loss), notable safety concerns, sustainability issues, and widespread quality control problems in the commercial market. For most people seeking appetite control and weight management, evidence-based approaches such as high-fiber diets, adequate protein intake, behavioral interventions, and (when appropriate) medical consultation about prescription options will be more effective and safer than Hoodia supplementation. If you choose to try Hoodia, do so only with CITES-certified, third-party-tested products, start with low doses, and monitor carefully for cardiovascular and other adverse effects.
Key Safety Points: Hoodia should be avoided by anyone with heart disease, high blood pressure, diabetes, liver disease, bleeding disorders, eating disorders, thyroid conditions, or kidney disease. It is contraindicated in pregnancy, breastfeeding, and pediatric populations. Drug interactions are a concern with cardiovascular medications, diabetes medications, blood thinners, antidepressants, and other stimulants. The elevated heart rate and blood pressure documented in human studies are clinically significant safety concerns, not minor effects.
Special Note: The supplement industry has marketed Hoodia aggressively over the past two decades with claims that significantly exceed the scientific evidence. This is a case where consumer enthusiasm has driven a market that scientific research has not validated. Furthermore, the sustainability concerns are significant; wild Hoodia populations have been depleted by demand, and purchasing unverified products may contribute to illegal harvesting of an endangered species. If you are committed to trying Hoodia despite these concerns, prioritize CITES certification, third-party authenticity testing, and conservative dosing while monitoring for adverse effects. Always consult with your healthcare provider before starting Hoodia, particularly if you take any medications or have any chronic health conditions.