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Dietary supplement

Fat Blocker Ingredients & Drug Interactions

by Greens First Lean

Fat Blocker label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Fat Blocker against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Fat Blocker is a dietary supplement by Greens First Lean with 1 active ingredient. Its ingredients are commonly taken for blood sugar control, high cholesterol, hangover symptoms.Based on those ingredients, 86 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are NeOpuntia. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Fat Blocker by Greens First Lean

Ask about any prescription or over-the-counter medication and we check it for interactions with Fat Blocker by Greens First Lean — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Fat Blocker by Greens First Lean

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Greens First Lean has one active ingredient: NeOpuntia, a form of prickly pear cactus. The capsule itself is made from vegetable material.

Prickly pear cactus is used traditionally to help manage blood sugar and cholesterol, though the evidence for some of those uses is stronger than others.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Prickly Pear Cactus's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: promotes fat excretion and healthy blood lipid levels.
  • We looked for evidence on: Hypercholesterolemia, Familial hypercholesterolemia, Metabolic syndrome, Obesity, cardiovascular risk, triglycerides — and 1 related terms.
  • The closest evidence on file: Prickly Pear Cactus is rated "Insufficient Reliable Evidence To Rate" for Familial hypercholesterolemia (Natural Medicines).
  • Also on file: Prickly Pear Cactus is rated "Insufficient Reliable Evidence To Rate" for Hypercholesterolemia, Obesity, Metabolic syndrome.

Prickly pear cactus is possibly effective for diabetes. The evidence for its other uses—age-related cognitive decline, benign prostatic hyperplasia (enlarged prostate), indigestion, and high cholesterol—is insufficient to rate, meaning we don't have enough reliable data yet to know whether it works for those conditions.

The evidence, ingredient by ingredient Prickly Pear Cactus

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Prickly pear cactus is generally well tolerated when taken by mouth. The most common side effects are mild: abdominal fullness, indigestion, diarrhea, and nausea.

Rare cases of headache, insomnia, and dizziness have been reported in clinical studies. There isn't enough safety data to recommend this supplement during pregnancy or while breastfeeding—talk with your doctor or pharmacist for personalized advice if you're pregnant, planning pregnancy, or nursing.

Side effects, ingredient by ingredient Prickly Pear Cactus

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Prickly Pear Cactus.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: diabetes medications.
  • For scale: 86 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take antidiabetes drugs (such as chlorpropamide, glyburide, glipizide, or metformin), you must check with your pharmacist before starting this product—there's a Moderate risk of low blood sugar when combined.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Greens First Lean may help with blood sugar management if you have diabetes, but it carries a real risk of low blood sugar when combined with antidiabetes medications. If you take chlorpropamide, glyburide, glipizide, metformin, or any other diabetes drug, check with your pharmacist first and monitor your glucose levels.

Otherwise, it's generally well tolerated and may cause mild digestive side effects.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Oct 24, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Fat Blocker, straight from the product label.

Brand Greens First Lean
Barcode (UPC) 853367008482
Net contents 90 Vegetable Capsule(s)
Market status On market
Date entered into DSLD Oct 24, 2024
DSLD ID 312854
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Organic, No Allergies, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Fat Blocker by Greens First Lean, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
3 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
Servings per container
30
UPC/BARCODE
853367008482
IngredientAmount% DV
NeOpuntia1800 mg--

Other ingredients: Vegetable capsule

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formulation

Promotes fat excretion Promotes healthy blood lipid levels Promotes cardiovascular health Promotes management of risk factors associated with Metabolic Syndrome

Made in USA

100% plant based

Organic

Allergen free GMO free

Vegetarian Suitable for vegans and vegetarians

Formula

Contains 100% natural and organic NeOpuntia

FDA Disclaimer Statement

These statements have not been evaluated by the Food & Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Recommended use: For best efficiency, take 3 capsules 15-45 minutes after each meal or as directed by your healthcare provider.

Brand IP Statement(s)

NeOpuntia is a product of NEXIRA

Precautions

Keep out of reach of children.

Do not use if safety seal is open or broken.

Storage

Storage: Store in cool dry place.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Fat Blocker by Greens First Lean label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Fat Blocker label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Fat Blocker by Greens First Lean

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

NeOpuntia

Interacts with
86 drugs
1800 mg per serving Form: Opuntia ficus-indica Leaf Powder

Prickly pear cactus is a desert plant whose pads and fruit are eaten as food and taken as a supplement, mainly for blood sugar, cholesterol, and hango...

NeOpuntia monograph & interactions

Other (inactive) ingredients: Vegetable capsule. These complete the product’s ingredient list but are not active constituents.

Interaction report

Fat Blocker by Greens First Lean Drug Interactions

Want to check YOUR meds against Fat Blocker?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
86Drugs
86 Moderate

Ingredients driving the most interactions

NeOpuntia 86

Individual Drug Interactions

The ingredients in Fat Blocker interact with 86 drugs. Click any drug to see the details.

1 of the 1 ingredient in Fat Blocker interact with drugs. Each result below shows which ingredient is responsible. NeOpuntia

Each ingredient & the kinds of drugs it affects

For each ingredient in Fat Blocker with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

NeOpuntia1 drug type · 86 drugs

Antidiabetes Drugs

Combining prickly pear cactus with antidiabetes drugs might increase the risk of hypoglycemia.
Case reports show that combining prickly pear cactus with antidiabetes drugs such as chlorpropamide, glyburide, glipizide, and metformin can increase the risk of hypoglycemia in patients with type 2 diabetes. Advise patients to monitor glucose levels closely. Dose adjustments may be necessary.

Likelihood Probable Evidence D
NeOpuntia full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Fat Blocker, from the product label.

Greens First Lean

See all Greens First Lean products
Name
Ceautamed Worldwide, LLC
Street Address
1289 Clint Moore Road
City
Boca Raton
State
FL
ZipCode
33487
Phone Number
866-409-6262
Web Address
GreensFirst.com
Pharmacist Counseling Corner

Fat Blocker by Greens First Lean: Common Questions

Does Fat Blocker by Greens First Lean interact with any medications?
Yes. Based on its ingredients, Fat Blocker has a known interaction with 86 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Fat Blocker contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this if I'm pregnant or breastfeeding?
There isn't enough safety data on prickly pear cactus supplements during pregnancy or while breastfeeding. Talk with your doctor or pharmacist about whether it's appropriate for you personally before taking it.
What are the most common side effects?
Mild digestive issues are the most common: abdominal fullness, indigestion, diarrhea, and nausea. Headache, insomnia, and dizziness are rare.
Does this product actually help with diabetes?
Prickly pear cactus is possibly effective for diabetes based on available evidence. However, it can increase your risk of low blood sugar if you're already taking antidiabetes medications, so don't use it without your doctor's approval.
Will it help me lose weight or block fat?
The evidence we hold doesn't establish that prickly pear cactus is effective for weight loss or fat blocking. It may help with blood sugar and cholesterol, but that's a different claim than fat blocking.
Is prickly pear cactus the same whether it's a supplement or a food?
Prickly pear cactus is generally well tolerated when eaten as a food, but supplement safety is less studied. As a supplement in concentrated form like this, it carries documented risks—particularly with antidiabetes drugs—that don't apply the same way to food amounts.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Fat Blocker is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Fat Blocker label
Go deeper

The Full Monographs Behind Fat Blocker’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Prickly Pear Cactus

Interacts with 86 drugs

Prickly pear cactus is a desert plant whose pads and fruit are eaten as food and taken as a supplement, mainly for blood sugar, cholesterol, and hangover symptoms. Some small studies suggest...

Read the full Prickly Pear Cactus monograph →
Sources

Sources & How We Checked

Fat Blocker's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 9 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Prickly Pear Cactus 9 references
  1. Meckes-Lozyoa M, Roman-Ramos R. Opuntia streptacantha; a coadjutor in the treatment of diabetes mellitus. Am J Chin Med 1986;14:116-8.
  2. Rayburn K, Martinez R, Escobedo M, et al. Glycemic effects of various species of nopal (Opuntia sp.) in type 2 diabetes mellitus. Texas J Rural Health 1998;26:68-76.
  3. Bush TM, Rayburn KS, Holloway SW, et al. Adverse interactions between herbal and dietary substances and prescription medications: a clinical survey. Altern Ther Health Med 2007;13:30-5.
  4. Sobieraj DM, Freyer CW. Probable hypoglycemic adverse drug reaction associated with prickly pear cactus, glipizide, and metformin in a patient with type 2 diabetes mellitus. Ann Pharmacother 2010;44:1334-7. PubMed
  5. Kleiner, O., Cohen, Z., and Mares, A. J. Low colonic obstruction due to Opuntia ficus indica seeds: the aftermath of enjoying delicious cactus fruits. Acta Paediatr. 2002;91(5):606-607.
  6. Steinberg, J. M. and Eitan, A. Prickly pear fruit bezoar presenting as rectal perforation in an elderly patient. Int J Colorectal Dis. 2003;18(4):365-367. PubMed
  7. Meckes-Lozyoa, M. and Roman-Ramos, R. Opuntia streptacantha: a coadjutor in the treatment of diabetes mellitus. Am J Chin Med 1986;14(3-4):116-118.
  8. Onakpoya IJ, O'Sullivan J, Heneghan CJ. The effect of cactus pear (Opuntia ficus-indica) on body weight and cardiovascular risk factors: a systematic review and meta-analysis of randomized clinical trials. Nutrition. 2015;31(5):640-6. PubMed
  9. Han EH, Lim MK, Lee S, et al. Efficacy of Ethanolic Extract of Opuntia ficus-indica var. saboten Stems for Improving Cognitive Function in Elderly Subjects 55-85 Years of Age: A Randomized, Double-Blind, Placebo-Controlled Study. J Med Food 2020;23(11):11

See these in context on the Prickly Pear Cactus monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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