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Nopal is the flat, green pad of the prickly pear cactus (Opuntia), eaten as a vegetable called nopales in Mexican cooking. A cooked cup has only about 22 calories but supplies 3 grams of fiber, about a fifth of the Daily Value for calcium and a sixth for magnesium, according to USDA data. Nopal benefits for blood sugar get the most attention: small studies found lower blood glucose after meals that included nopal, but the trials are short, small and often at high risk of bias. Below are the USDA numbers for nopales and the prickly pear fruit, what the research measured, how supplements differ from the vegetable, and who should talk to a clinician first.
Peptide Labs does not sell nopales or prickly pear fruit; one supplement we carry lists prickly pear leaf extract, covered below. This article is general nutrition information, not medical advice.
Key Takeaways
- A cooked cup of nopales has about 22 calories, 3 grams of fiber and 19% of the Daily Value for calcium in USDA data.
- The prickly pear fruit is a different food from the pad, with more sugar and more magnesium.
- Small meal studies found lower post-meal blood glucose with nopal; reviews rate much of this evidence as low quality.
- A 2015 meta-analysis found no significant effect of prickly pear cactus products on body weight.
- People on blood sugar medicines should ask their clinician before adding nopal supplements or large daily servings.
What is nopal? Pads, fruit and the prickly pear cactus
Opuntia cacti are native to the Americas and are now grown in many dry regions. Two parts are eaten. The pads, botanically called cladodes, are the nopales: they are de-spined, sliced and cooked, or sold in jars as nopalitos. The fruit, called tuna in Spanish and sold as prickly pear, grows on the edge of the pads and is eaten raw or made into juice and syrups.
Researchers stress that the two parts should not be confused. A 2019 systematic review (Gouws and colleagues, Medicina) found that studies using the pad and studies using the fruit reached different results, and some papers did not say which part they tested. When you read a claim about nopal cactus, check whether it refers to the pad, the fruit or a powdered extract.
Nopal nutrition per cup (USDA)
The table uses USDA FoodData Central SR Legacy entries: cooked nopales without salt (FDC 169388), raw nopales (FDC 168571) and raw prickly pear fruit (FDC 167750). Percent Daily Values (%DV) use the FDA Daily Values printed on Nutrition Facts labels.
| Nutrient | Nopales, cooked (1 cup, 149 g) | Nopales, raw (1 cup, 86 g) | Prickly pear fruit (1 fruit, 103 g) |
|---|---|---|---|
| Calories | 22 | 14 | 42 |
| Carbohydrate | 4.9 g (2%) | 2.9 g (1%) | 9.9 g (4%) |
| Fiber | 3.0 g (11%) | 1.9 g (7%) | 3.7 g (13%) |
| Protein | 2.0 g (4%) | 1.1 g (2%) | 0.8 g (2%) |
| Calcium | 244 milligrams (19%) | 141 milligrams (11%) | 58 milligrams (4%) |
| Magnesium | 70 milligrams (17%) | 45 milligrams (11%) | 88 milligrams (21%) |
| Potassium | 291 milligrams (6%) | 221 milligrams (5%) | 227 milligrams (5%) |
| Vitamin C | 7.9 milligrams (9%) | 8.0 milligrams (9%) | 14.4 milligrams (16%) |
| Manganese | 0.61 milligrams (26%) | 0.39 milligrams (17%) | Not listed |
Nopales are about 94% water, which is why the calorie count is so low. Their fiber puts them among low-calorie fiber-rich foods, and their magnesium adds to the vegetables on our list of magnesium sources. A single cooked pad weighs about 29 grams in USDA data and has roughly 4 calories, so a typical side dish uses several pads. Nopales are not a meaningful protein source, and the cooked entry is for nopales prepared without salt, so check the sodium line on the label of jarred nopalitos.
Nopal benefits: what the research shows
Most nopal research comes from Mexico, where small studies since the 1980s have tested nopal with meals in healthy volunteers and in people with type 2 diabetes. The results below are research summaries, not health claims. Nopal is not a substitute for diabetes care, and anyone managing blood sugar should work with their clinician.
Blood sugar after meals
In a 2014 study in the Journal of the Academy of Nutrition and Dietetics (López-Romero and colleagues), researchers first measured the glycemic index of dehydrated nopal in 7 healthy volunteers and found it low, at about 32. They then gave 14 Mexican adults with type 2 diabetes a high-carbohydrate breakfast or a high-soy-protein breakfast, with or without steamed nopal. Adding nopal to the high-carbohydrate breakfast lowered the rise in blood glucose and insulin over the next few hours. These were single-meal tests in a handful of people, so they show a short-term effect on one meal, not long-term blood sugar control.
The 2019 Gouws review pulled together 20 controlled human studies. Studies of the pad and of some combined Opuntia products mostly reported lower glucose and insulin, while studies of the fruit mostly found no significant effect. The authors noted that the pad and fruit studies carried a high risk of bias. One proposed explanation for the meal effect is viscous fiber slowing digestion, the same idea behind a soluble fiber supplement, although this has not been proven for nopal specifically.
Cholesterol, body weight and other claims
- Blood lipids: a 2020 systematic review by the same group (11 studies, Complementary Therapies in Medicine) found that prickly pear fruit was linked with lower total and LDL cholesterol in most studies, while the pad had little effect on lipids. Study quality and the part of the plant used varied widely.
- Body weight: a 2015 meta-analysis of five randomized trials (Onakpoya and colleagues, Nutrition) found no significant difference in body weight between Opuntia ficus-indica products and control groups. It did report small changes in body fat percentage, blood pressure and total cholesterol, but the trials were few, varied in design and were inconsistently reported.
- Hangovers: a 2004 NIH-funded crossover trial (Wiese and colleagues, Archives of Internal Medicine) gave 64 young adults a prickly pear extract or a placebo before drinking, and 55 finished both rounds. Nausea, dry mouth and loss of appetite were milder with the extract, but the overall symptom score did not reach statistical significance. One trial is not enough to call nopal a hangover remedy.
| Study | Who | What it found | Limits |
|---|---|---|---|
| López-Romero 2014 | 7 healthy adults; 14 adults with type 2 diabetes | Lower post-meal glucose and insulin when nopal was added to a high-carbohydrate breakfast | Single meals, very small groups |
| Gouws 2019 review | 20 controlled human studies | Pad studies mostly lowered glucose; fruit studies mostly did not | High risk of bias in pad and fruit studies |
| Gouws 2020 review | 11 studies | Fruit linked with lower total and LDL cholesterol; pad effect small | Mixed products, plant part often unclear |
| Onakpoya 2015 meta-analysis | 5 randomized trials | No significant effect on body weight | Few trials, inconsistent reporting |
| Wiese 2004 trial | 64 young adults | Some hangover symptoms milder; total score not significant | Single trial, one extract |
The 2014 study also measured GLP-1, a gut hormone released after meals. A food that changes post-meal hormone levels a little is very different from a prescription GLP-1 medicine; our explainer on what GLP-1 is covers the difference.
Nopal supplements vs the vegetable
Nopal is sold as capsules, powders and juices, often made from dried pads. These products are dietary supplements, so the FDA does not review them for effectiveness before sale, and the amount of pad, the part of the plant and the processing vary from brand to brand. A capsule also delivers far less fiber than a cooked cup of nopales, so results from meal studies may not carry over.
In our store, the only product whose label lists this ingredient is Hydroxycut +Women, which includes prickly pear leaf extract inside a proprietary blend with green coffee bean extract and caffeine. The label does not disclose how much prickly pear is in the blend, so it should not be thought of as a nopal supplement. Its warning panel says one serving has up to as much caffeine as 2 cups of coffee, that it is not for anyone under 18 or who is pregnant or nursing, and that it should not be combined with other caffeine sources; see our guide to caffeine limits.
Who should be careful with nopal
Cooked nopales are an everyday food for millions of people. Extra care makes sense in these situations:
- Blood sugar medicines: because studies report lower post-meal glucose, adding nopal supplements or large daily servings on top of insulin or other glucose-lowering medicines could add to their effect. Talk to your clinician before making a change, and do not adjust medicines on your own.
- Digestive upset: the 2015 meta-analysis listed gastric intolerance among reported side effects, and more fiber than usual can cause gas or bloating.
- Large amounts of the fruit: prickly pear fruit is full of hard seeds. A 2015 case report described rectal impaction from a seed mass after eating a lot of the fruit and noted about 20 similar cases in the medical literature.
- Pregnancy and breastfeeding: there is little safety research on concentrated nopal supplements, so ask your obstetric clinician first.
- Handling fresh pads and fruit: both carry spines and fine bristles, so use gloves or choose pads that have already been cleaned.
If you are interested in other plants studied for blood sugar, our sibling guide to bitter melon covers a vegetable with a similar reputation and more safety cautions.
Frequently Asked Questions
What is nopal?
Nopal is the edible pad of the prickly pear cactus. Cooked and sliced, it is sold as nopales or nopalitos and is common in Mexican cooking.
What are the main nopal benefits?
USDA data show nopales are very low in calories and provide fiber, calcium, magnesium and manganese. Small studies found lower blood glucose after meals that included nopal, but the evidence is limited.
Are nopales and prickly pear fruit the same?
No. Nopales are the pads and prickly pear is the fruit. Research on one does not automatically apply to the other.
Can nopal replace diabetes medicine?
No. The studies are small and short. Anyone with diabetes should keep following their care plan and ask their clinician before adding nopal supplements.
Does nopal help with weight loss?
A 2015 meta-analysis of randomized trials found no significant effect of prickly pear cactus products on body weight.
Is nopal safe to eat every day?
As a cooked vegetable it is a traditional everyday food. Concentrated supplements have less safety data, so check with a clinician if you take medicines or are pregnant.
Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines for blood sugar, are pregnant or have a chronic condition. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Last reviewed October 2026.
Related guides: Bitter Melon: Nutrition, Blood Sugar Research and Side Effects, High Fiber Foods: USDA List of Fruits, Vegetables, Beans and Grains, Berberine Benefits: What the Research Shows and What It Does Not.