Cactus (nopales): pooled trials of the supplements found no change in weight

Cactus on a plate means nopales, the flat pads of the prickly pear, and most of the research tests pills and powders made from the plant. A meta-analysis of 5 randomized trials of Opuntia ficus-indica supplements found no significant change in body weight, a mean difference of -1.8 lb (-0.83 kg) with a 95% interval from -2.49 to 0.83. The trials disagreed sharply with one another (I2 = 93%) and mixed products made from the fruit and from the pad. The one clear weight result came from a patented Opuntia fiber complex. In 123 overweight adults on a calorie-reduced diet, 3 g a day for 12 weeks gave 8.4 lb (3.8 kg) of weight loss against 3.1 lb (1.4 kg) on placebo, in a trial funded by the maker. In the US, supplements do not go through FDA approval the way medicines do, so anyone who takes medication, is pregnant or has a chronic illness should talk to a doctor before taking an Opuntia supplement. The vegetable itself is a modest source of minerals. Per 100 g raw, USDA lists 164 mg calcium, 52 mg magnesium and 9.3 mg vitamin C, from one record with no spread across samples, and in the USDA survey table one pad weighs 1.1 oz (30 g).

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• USDA lists 164 mg calcium, 52 mg magnesium and 9.3 mg vitamin C per 3.5 oz (100 g) of raw nopales (cactus pads), from a reference record with no sample spread. — USDA SR Legacy record Nopales, raw, FDC 168571 Evidence E source
  Per 100 g raw: calcium 164 mg (13% DV), magnesium 52 mg (12% DV), vitamin C 9.3 mg (10% DV)

What a real portion looks like

• In the USDA survey food table one cactus pad weighs 1.1 oz (30 g) and one cup of raw or cooked cactus weighs 5.3 oz (150 g). — USDA FNDDS: Cactus, raw (code 75105500); Cactus, cooked, no added fat (code 75213110) Evidence E source
  1 pad 30 g; 1 cup 150 g; quantity not specified 75 g
• In 14 people with type 2 diabetes, adding 300 g steamed nopal to a high-carbohydrate breakfast lowered the glucose area under the curve from 443 to 287. — 14 Mexican patients with type 2 diabetes, high-carbohydrate breakfast with or without 300 g steamed nopal (n = 14) Evidence C source
  Glucose AUC 287 ± 30 with nopal vs 443 ± 49 without; insulin iAUC 5,952 vs 7,313

What your body absorbs

• In 7 healthy volunteers, dehydrated nopal had a glycemic index of 32.5 and an insulinemic index of 36.1 against glucose. — 7 healthy participants, 50 g available carbohydrate from glucose or dehydrated nopal (n = 7) Evidence C source
  GI 32.5 ± 4; insulinemic index 36.1 ± 6; GLP-1 index 25.9 ± 18

What cooking and storage change

• In USDA reference data, cooked nopales carry 5.3 mg vitamin C per 3.5 oz (100 g) against 9.3 mg raw, while magnesium drops only from 52 to 47 mg. — USDA SR Legacy records Nopales, raw and Nopales, cooked, without salt Evidence E source
  Vitamin C 9.3 mg raw vs 5.3 mg cooked per 3.5 oz (100 g); magnesium 52 vs 47 mg

What it does to your health

• In a 12-week trial in 123 overweight adults on a calorie-reduced diet, 3 g a day of an Opuntia fiber complex led to 8.4 lb (3.8 kg) weight loss versus 3.1 lb (1.4 kg) on placebo. — 123 overweight and obese adults, hypocaloric diet, 3 g/day IQP G-002AS or placebo for 12 weeks (n = 123) Evidence B source
  Weight change -3.8 ± 1.8 kg vs -1.4 ± 2.6 kg (P < 0.001)

Safety, limits and interactions

• The same meta-analysis of 5 randomized Opuntia trials recorded gastric intolerance and flu symptoms as adverse events. — 5 randomized clinical trials of Opuntia ficus-indica supplementation (n = 5 trials) Evidence A source
  Adverse events reported: gastric intolerance, flu symptoms; frequency not given in abstract
• In a one-week trial in 60 people with IBS, 20 g a day of nopal fiber gave adequate symptom relief in 87% versus 33% on placebo, while 30 g a day caused more loose stools. — 60 adults meeting Rome IV criteria for IBS, 10, 20 or 30 g/day nopal fiber or dextrose for 1 week (n = 60) Evidence B source
  Adequate relief 87% (20 g/day) and 80% (30 g/day) vs 33% placebo; more loose stools at 30 g/day (p = 0.027)
• In a 16-week placebo-controlled trial in 29 obese pre-diabetic adults, 200 mg a day of an Opuntia extract showed no between-group differences in blood safety parameters. — 29 obese pre-diabetic men and women aged 20 to 50, 200 mg OpunDia (n=15) or placebo (n=14) for 16 weeks (n = 29) Evidence B source
  No between-group differences in comprehensive metabolic panel, insulin, HbA1c or body composition
• A case report describes barrel cactus spines causing severe pain, swelling and months of slow healing in an 18-year-old after skin contact. — one 18-year-old woman with multiple barrel cactus spine injuries (n = 1) Evidence D source
  Intense erythematous reaction within 8 to 10 hours; lesions improved over several months
• Cactus (nopal) products sold as dietary supplements in the US fall under DSHEA (1994), so the FDA does not approve them for safety or effectiveness before they are sold. — Dietary supplements sold in the United States Evidence E source
  No FDA premarket approval of safety, effectiveness or labeling

What people believe that the data does not support

• A meta-analysis of 5 randomized trials found Opuntia ficus-indica supplements did not significantly change body weight (mean difference -1.8 lb (-0.83 kg)). — 5 randomized clinical trials of Opuntia ficus-indica supplementation (n = 5 trials) Evidence A source
  Body weight MD -1.8 lb (95% CI -5.5 to 1.8; metric: -0.83 kg, -2.49 to 0.83), I2 = 93%
• The EU did not authorize the claim that NeOpuntia, dried prickly pear cactus leaves, helps improve blood lipids and HDL cholesterol. — EU Register of nutrition and health claims, snapshot 2026-09-21 Evidence E source
  Status: Non-authorized

Who this works differently for

• In a 6-week trial in women with metabolic syndrome, 39% on dried Opuntia leaf capsules (1.6 g per meal) no longer met the diagnosis versus 8% on placebo. — 68 women aged 20 to 55 with metabolic syndrome, BMI 25 to 40, 59 completers, 6 weeks (n = 68) Evidence B source
  No longer metabolic syndrome at study end: 39% NeOpuntia vs 8% placebo; HDL-C rise in women over 45
• In 69 women aged 40 to 60, 5 g a day of calcium-rich nopal powder for 24 weeks did not change bone mineral density. — 69 women aged 40-60, 5 g/day nopal powder (n=56) or habitual diet (n=13) for 24 weeks (n = 69) Evidence C source
  No significant change in BMD (P = .885 nopal group), BMI, body fat or serum calcium

What is still unknown

• A systematic review of 11 studies found lipid effects of eating Opuntia cladodes were small, and noted that studies often confuse the fruit with the pad. — 11 human studies of Opuntia fruit (6), cladode (4) or commercial products (1) (n = 11 studies) Evidence C source
  Cladode: small effect, one subgroup HDL-C increase; fruit: TC reductions in most studies
• A systematic review of 45 laboratory and animal studies on Opuntia dillenii found no toxic effects, while noting that human trials are still missing. — 45 in vitro and in vivo studies on Opuntia dillenii (n = 45 studies) Evidence D source
  Consistent absence of toxic effects across routes and doses tested; no human trials

The bottom line

For blood sugar the evidence on the vegetable is small and not randomized. In 14 Mexican adults with type 2 diabetes, adding 11 oz (300 g) of steamed nopal, about 2 cups, to a high-carbohydrate breakfast lowered the glucose area under the curve from 443 to 287 after that single meal. In 7 healthy volunteers, dried nopal had a glycemic index of 32.5. Neither study allocated people at random, so both are early signals. A review of 11 human studies found the effect of the pads on blood lipids small, and warned that many studies confuse the fruit with the pad. Several positive trials used branded products. In 68 women with metabolic syndrome, capsules of dried Opuntia leaf at 1.6 g per meal for 6 weeks left 39% no longer meeting the diagnosis, against 8% on placebo, in a trial of a patented powder funded by its maker. The EU did not authorize that product's claim on blood lipids and HDL cholesterol, which means the evidence was judged insufficient when it was assessed. In 69 women aged 40 to 60, 5 g a day of calcium-rich nopal powder for 24 weeks did not change bone mineral density, in a trial with no randomization and only 13 controls. Cooking lowers the vitamin C. USDA lists 5.3 mg per 3.5 oz (100 g) cooked against 9.3 mg raw, while magnesium goes from 52 to 47 mg, figures from two separate records that do not adjust for water. The meta-analysis of supplements recorded stomach intolerance and flu symptoms as side effects, without saying how often. In a one-week trial in 60 adults with irritable bowel syndrome, 20 g a day of extracted nopal fiber gave adequate relief to 87% against 33% on placebo, and 30 g a day caused more loose stools. A 16-week trial of 200 mg a day of an Opuntia extract in 29 obese pre-diabetic adults found no difference from placebo in routine blood safety tests. Cactus spines puncture skin with light pressure, and in a case report of an 18-year-old hurt by an ornamental barrel cactus the lesions took months to heal. Laboratory and animal studies of a related species, Opuntia dillenii, found no toxic effects, and there are no human trials of it. We found no study of nopales with medicines, in pregnancy or in kidney disease, and none on how much of their calcium the body absorbs. That includes glucose-lowering drugs, although the meal test above found nopal lowered post-meal glucose in people with type 2 diabetes. The 300 g in that test was one meal, not a tested daily amount. Anyone who takes insulin or another glucose-lowering medicine should talk to their doctor before eating nopales regularly or in portions like that one, and check their blood glucose if they do.

Sources

1. cact-r2-01 · food composition dataset
   Nopales, raw | FDC 168571 | sr_legacy | Calcium, Ca 164 MG | Magnesium, Mg 52 MG | Vitamin C 9.3 MG
   USDA FoodData Central, SR Legacy (2018), FDC 168571 · checked 2026-09-28
2. cact-r2-03 · survey food dataset
   Cactus, raw | FNDDS code 75105500 | fdc_id 2709776 | 1 cup 10205 = 150 g | 1 pad 61595 = 30 g | Quantity not specified 90000 = 75 g
   USDA FNDDS (survey foods) · checked 2026-09-28
3. cact-r2-08 · controlled clinical trial
   For those patients with type 2 diabetes who consumed the HCB+nopal, there was significantly lower area under the curve for glucose (287±30) than for those who consumed the HCB only (443±49), and lower incremental area under the curve for insulin (5,952±833 vs 7,313±1,090), and those patients with type 2 diabetes who consumed the HSPB avoided postprandial blood glucose peaks.
   J Acad Nutr Diet, 2014 · checked 2026-09-28
4. cact-r2-07 · controlled clinical trial
   The glycemic index of nopal was 32.5±4, insulinemic index was 36.1±6, GIP index was 6.5±3.0, and GLP-1 index was 25.9±18.
   J Acad Nutr Diet, 2014 · checked 2026-09-28
5. cact-r2-02 · food composition dataset
   Nopales, raw | Vitamin C 9.3 MG | Magnesium, Mg 52 MG || Nopales, cooked, without salt | Vitamin C 5.3 MG | Magnesium, Mg 47 MG
   USDA FoodData Central, SR Legacy (2018), Nopales raw and cooked without salt · checked 2026-09-28
6. cact-r2-12 · randomized controlled trial
   The mean body weight change from baseline was 3.8 ± 1.8 kg in IQ vs. 1.4 ± 2.6 kg in placebo (P < 0.001).
   Obesity (Silver Spring), 2013 · checked 2026-09-28
7. cact-r2-05 · meta-analysis
   Adverse events included gastric intolerance and flu symptoms.
   Nutrition, 2015 · checked 2026-09-28
8. cact-r2-06 · randomized controlled trial
   Significantly more patients reported adequate relief of symptoms after 20 g/day (87%, p = 0.008) and 30 g/day (80%, p = 0.025) of nopal fiber compared to placebo (33%).
   Neurogastroenterol Motil, 2021 · checked 2026-09-28
9. cact-r2-11 · randomized controlled trial
   There were no between-group differences found with the OGTT time points, area under the curve, blood chemistry variables (insulin, hsCRP, adiponectin, proinsulin, Hb1Ac), diet analysis variables (carbohydrates, fat, protein and total kcals), body composition variables (fat mass, fat free mass, percent body fat and total body weight), or blood chemistry safety parameters (comprehensive metabolic panel) pre-to-post 16-week intervention.
   J Ethnopharmacol, 2010 · checked 2026-09-28
10. cact-r2-15 · case report
    The spines or glochidia can easily puncture the skin with only minor pressure (ie, bumping or touching the cactus).
    Wounds, 2017 · checked 2026-09-28
11. sf-dshea-6 · agency advice
    The Federal Food, Drug, and Cosmetic Act was amended in 1994 by the Dietary Supplement Health and Education Act, often referred to as DSHEA, which defined “dietary supplement” and set out the FDA’s authority regarding such products....The FDA does NOT have the authority to approve dietary supplements for safety and effectiveness, or to approve their labeling, before the supplements are sold to the public.
    FDA, FDA 101: Dietary Supplements · checked 2026-10-08
12. cact-r2-04 · meta-analysis
    Meta-analysis revealed a nonsignificant difference in body weight between OFI and controls (mean difference = -0.83 kg; 95% confidence interval, -2.49 to 0.83; I(2) = 93%).
    Nutrition, 2015 · checked 2026-09-28
13. cact-r2-10 · EU claim register entry
    POL-HC-6279 NeOpuntia®, containing dehydrated leaves of the prickly pear cactus (Opuntia ficus-indica) NeOpuntia® helps to improve blood lipid parameters associated with cardiovascular risks, especially the HDL-cholesterol. -/- Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6279, snapshot 2026-09-21 · checked 2026-09-28
14. cact-r2-09 · randomized controlled trial
    At the study end, 39% of the NeOpuntia group, but only 8% of the placebo group, were no longer diagnosed with metabolic syndrome.
    Adv Ther, 2007 · checked 2026-09-28
15. cact-r2-13 · controlled clinical trial
    These results indicate that advanced maturation NP does not have influence in bone health, BMI, and body composition in adult women.
    J Med Food, 2020 · checked 2026-09-28
16. cact-r2-14 · systematic review
    Separately, the effect of CLD consumption on lipids was small with one study reporting a significant increase in plasma HDL-C in a subgroup of participants (>45 years of age) following consumption of a patented CLD powder product.
    Complement Ther Med, 2020 · checked 2026-09-28
17. cact-r2-16 · systematic review
    Across the studies reviewed, there is a consistent indication of an absence of toxic effects for the different routes of administration and doses tested, suggesting a favorable safety profile under the experimental conditions.
    Nutrients, 2025 · checked 2026-09-28