SkinnyFit NLP-1 GLP-1 Review: 1,000 mg Berberine in a Crowded Category

Key Takeaways

NLP-1 is the simplest of the GLP-1-branded products we have reviewed: one well-studied ingredient at a reasonable dose plus supporting ingredients at small amounts, with no caffeine. Its weak points are disclosure and marketing. The listings we reviewed name a 12-strain probiotic blend without strain identifiers or a guaranteed count, and give no turmeric amount. The brand's landing page headline, "Lose weight, even if you cheat," promises more than any of the ingredients can show. Berberine's weight effect in meta-analyses averages under a kilogram ( Elahi Vahed et al., 2026, Int J Obes). Berberine also slows the liver enzymes that clear many medicines ( Guo et al., 2012, Eur J Clin Pharmacol), so check with a pharmacist first if you take prescription drugs. For how this category compares with prescription GLP-1 drugs, see our GLP-1 supplement guide.

SkinnyFit GLP-1 review: NLP-1 or GLP-1 Natural?

They are the same formula under two names. SkinnyFit's current landing page uses "NLP-1," while many retailer listings still call it "GLP-1 Natural Probiotic Supplement." Both describe berberine, chicory inulin, turmeric and a 12-strain probiotic blend in capsules, 30 servings per bottle.

The SkinnyFit product page describes the formula as 1,000 mg of berberine, 211 mg of chicory inulin, turmeric root and 12 probiotic strains, with hypromellose capsules, microcrystalline cellulose, magnesium stearate and silicon dioxide as other ingredients. It states the product has no GLP-1 drugs, no caffeine and no synthetics, and that it is made in a cGMP-certified facility.

SkinnyFit has not explained what "NLP-1" stands for. The page still compares the product directly with prescription GLP-1 injections, so the renaming changes the label more than the positioning. Buyers should treat it as a berberine supplement with gut-health extras, not as an alternative to a prescription.

What the label tells you, and what it leaves out

The label discloses the two ingredients that matter most for dosing, berberine and inulin. It does not disclose the amount of turmeric or curcuminoids, the identity of each probiotic strain, or a colony count guaranteed through the expiration date. Those gaps make three of the four ingredient groups impossible to compare with research.

Probiotic effects belong to individual strains rather than to whole species. Lactobacillus rhamnosus GG and another Lactobacillus rhamnosus strain can behave differently in trials. Without strain codes, there is no way to link this blend to any study. A count "at time of manufacture" also tells you less than a count guaranteed at expiration, because live bacteria die off during storage. Our label reading guide explains these lines in more detail, and our probiotic guide covers what a strong probiotic label looks like.

Turmeric root powder contains only a few percent curcuminoids. If the turmeric here is raw root at a modest weight, the curcumin content per capsule is small. If SkinnyFit uses a standardized extract, saying so would help buyers compare it.

Berberine at 1,000 mg: what the evidence supports

Berberine has the most human research of any ingredient in GLP-1-branded supplements. Trials in people with high blood sugar show reductions in fasting glucose, HbA1c and blood lipids, and meta-analyses show small reductions in body weight. Most trials used 900 to 1,500 mg a day, so 1,000 mg is a reasonable dose.

A meta-analysis of 14 randomized trials with 1,068 participants found that berberine combined with lifestyle changes lowered blood glucose and improved lipids more than lifestyle changes alone in adults with type 2 diabetes, though the authors cautioned that most trials were small and of low methodological quality ( Dong et al., 2012, Evid Based Complement Alternat Med). For weight, a 2026 meta-analysis of 23 trials reported an average body weight reduction of 0.88 kg, plus small decreases in BMI and waist circumference ( Elahi Vahed et al., 2026, Int J Obes). An earlier analysis found similar small changes, along with lower C-reactive protein ( Asbaghi et al., 2020, Clin Nutr ESPEN).

The GLP-1 connection is mostly mechanistic. In diabetic rats, berberine increased GLP-1 secretion ( Lu et al., 2009, J Endocrinol), and in intestinal cell models it triggered GLP-1 release through bitter taste receptor signaling ( Yu et al., 2015, Biochem Pharmacol). These findings explain why berberine is marketed under a GLP-1 banner, but the weight change seen in human trials is modest compared with prescription GLP-1 drugs.

Berberine is often split into two or three doses with meals in trials, partly because it is absorbed poorly and partly because it can upset the stomach. If you use NLP-1, follow the label directions, and if you get cramping or diarrhea, taking it with food usually helps. Our comparison of dihydroberberine and berberine covers absorption differences.

Does adding probiotics to berberine help? The PREMOTE trial

The best test of the berberine-plus-probiotics idea is the PREMOTE trial. In 409 adults with newly diagnosed type 2 diabetes at 20 centers in China, 12 weeks of berberine alone lowered HbA1c by about 0.99 percentage points, and berberine plus probiotics by about 1.04 points, both significantly more than placebo or probiotics alone. The probiotics added no significant benefit on top of berberine.

Zhang and colleagues randomly assigned participants to berberine alone, probiotics plus berberine, probiotics alone, or placebo ( Zhang et al., 2020, Nat Commun). HbA1c fell by about 0.59 points with placebo and 0.53 points with probiotics alone, so the probiotic blend used in that trial did not lower blood sugar by itself. The berberine groups had more gastrointestinal side effects. The researchers traced part of berberine's effect to changes in how gut bacteria process bile acids.

A secondary analysis of trial data reported that combining berberine with probiotics improved some measures of post-meal lipid levels ( Wang et al., 2022, Gut Microbes). That is a narrower finding and used a specific probiotic product.

The implication for NLP-1 buyers is straightforward. The berberine is doing the measurable work. The probiotic blend may help some people tolerate berberine or support general gut health, but the best trial of the combination did not show extra benefit on blood sugar, and NLP-1's strains are not identified, so even that trial's strains cannot be matched.

The inulin dose: why 211 mg is mostly symbolic

Chicory inulin is a fermentable prebiotic fiber, and fermentable fibers can raise GLP-1. The human study most often cited used 16 g a day of prebiotic fiber for two weeks. NLP-1 provides 211 mg, about 1% of that amount.

In the trial by Cani and colleagues, 10 healthy adults took 16 g a day of oligofructose or a placebo for two weeks. The prebiotic increased breath hydrogen about threefold, a sign of gut fermentation, raised plasma GLP-1 and PYY after a meal, and lowered hunger ratings ( Cani et al., 2009, Am J Clin Nutr). A separate study with a different fermentable fiber, 10 g of resistant maltodextrin, also delayed hunger after a meal ( Ye et al., 2015, Nutr Res).

At 211 mg, the inulin in NLP-1 is too small to expect a similar effect. It is not harmful, and it may be included partly as food for the probiotic bacteria. If you want the fiber effect, a teaspoon of inulin or another fiber powder added to food provides several grams. Our HUM Flatter Me Fiber review looks at a product built around a full fiber dose.

Safety: who should check before taking it

Berberine is generally well tolerated in trials, with digestive upset the most common side effect. The main concerns are drug interactions, added glucose lowering in people on diabetes medicine, and use in pregnancy and breastfeeding, where berberine should be avoided.

In a crossover study of healthy men, two weeks of berberine at 300 mg three times daily reduced the activity of CYP2D6, CYP2C9 and CYP3A4 ( Guo et al., 2012, Eur J Clin Pharmacol). These enzymes process many common drugs, including some statins, blood thinners, antidepressants and blood pressure medicines. Our berberine interaction guide lists the main ones.

People taking metformin, insulin or other glucose-lowering drugs should not add berberine without their clinician, since the combined effect could lower blood sugar more than intended. People on a prescription GLP-1 drug should also ask first: both berberine and GLP-1 drugs commonly cause nausea and diarrhea, and stacking them can make those effects worse. Berberine should be avoided during pregnancy and breastfeeding. Anyone with liver disease can read our berberine liver safety article before starting.

Price and value compared with simpler options

At roughly $50 to $63 for 30 servings, NLP-1 costs more than a standalone berberine supplement at a similar dose. What you pay extra for is the probiotic blend, the small inulin and turmeric additions, and the convenience of one product.

Given the PREMOTE results, the probiotic blend is the least certain part of that premium. If berberine is your goal, a third-party-tested standalone berberine product at 1,000 to 1,500 mg a day gives you the ingredient with the evidence at lower cost. If gut health is your goal, a probiotic that lists strain codes and a count at expiration lets you match it to research. Buying the two separately also lets you stop one without the other if you get side effects.

The listings we reviewed did not show a USP, NSF or ConsumerLab seal for NLP-1. Our third-party testing guide explains what to ask a brand when there is no certification.

Who should consider it and who should skip it

NLP-1 suits adults who want a stimulant-free berberine product in a single capsule and are comfortable with an undisclosed probiotic blend. It is a poor fit for anyone expecting prescription-level weight loss, anyone on medicines that interact with berberine, and anyone who wants to know exactly which probiotic strains they are taking.

Compared with the other two products in this group, NLP-1 has the most berberine per serving and no stimulants. Our Inno Shred GLP-1 review covers a stimulant-based alternative, and our Pendulum review covers a probiotic product that does disclose its strains.

Turmeric: what a small amount of root can and cannot do

Turmeric's main active compounds, curcuminoids, make up only a few percent of the root and are absorbed poorly unless paired with absorption enhancers or special formulations. Without a stated amount or standardization, the turmeric in NLP-1 is best seen as a minor ingredient rather than a dose you can match to research.

Curcumin trials usually test standardized extracts in the hundreds of milligrams to grams per day, often in formulations designed to improve absorption. A capsule that also has to hold 1,000 mg of berberine across the daily serving has limited room left, so the turmeric amount is likely modest. That is not a safety concern for most people, though turmeric supplements can interact with blood thinners at higher doses.

If you are interested in curcumin for its own sake, a separate product that states curcuminoid content and absorption technology is the way to get a known dose. For NLP-1, judge the product on its berberine.

How to read any GLP-1 probiotic label

A useful probiotic label names each strain with its strain code, gives a colony count per strain or a total count guaranteed through the expiration date, and states storage conditions. Labels that list only species, or only a number of strains, cannot be matched to clinical research.

Strain codes look like letters and numbers after the species name, for example Lactobacillus rhamnosus GG or Bifidobacterium animalis subsp. lactis BB-12. They matter because trials test specific strains, and results for one strain do not transfer automatically to another strain of the same species. Counts matter because many probiotic effects in trials depended on dose, typically in the billions of colony-forming units per day.

Akkermansia-based products are the main exception in how they count, since that bacterium is hard to grow on plates; some use active fluorescent units instead of CFU. NLP-1 does not list Akkermansia. If Akkermansia is what you are looking for, our Pendulum review covers a product built around it and explains the human Akkermansia trial ( Depommier et al., 2019, Nat Med).

Testing whether it works for you

The most reliable way to judge a berberine product is with numbers. If your clinician agrees, check fasting glucose, HbA1c and a lipid panel before starting, take the product consistently for about 12 weeks, then repeat the same tests. Body weight and waist measurements taken the same way each week add useful information.

Twelve weeks matches the length of the PREMOTE trial and many others, and HbA1c reflects average blood sugar over roughly three months. Shorter trials may show nothing simply because there was not enough time. Keep your diet and activity as steady as you can during the trial period so that any change is easier to attribute. Write down the brand, the dose and the days you missed, because inconsistent use is one of the most common reasons a supplement seems not to work. Bring the before-and-after results to your clinician rather than interpreting them alone.

If your numbers do not move, berberine may not be helping you, or the dose may be too low for your situation. If they do improve and you take medicine for blood sugar or cholesterol, tell your prescriber, since your medication may need to be adjusted. Do not stop or change prescription medicine on your own because of supplement results.

How NLP-1 compares with HUM and Inno Supps

Of the three GLP-1-branded products we reviewed together, NLP-1 has the most berberine in a single product and no stimulants. HUM's main GLP-1 product is a fiber drink, with berberine sold separately. Inno Shred pairs a smaller berberine dose with a strong stimulant blend.

The right choice depends on which single effect you want. For a fiber-based fullness effect with meals, a full fiber dose matters more than any brand name; see our HUM review. For stimulant energy, see the Inno Shred review and read its safety section first. For berberine, NLP-1 provides a reasonable dose, and a standalone berberine product provides the same ingredient with fewer unknowns.

Berberine timing, absorption and side effects

Berberine is poorly absorbed from the gut, and trials usually split the daily dose into two or three portions taken with meals. Digestive side effects such as cramping, constipation, diarrhea and nausea are the most common complaints and tend to ease when berberine is taken with food or the dose is spread out.

In the PREMOTE trial, the berberine groups reported more gastrointestinal side effects than the placebo and probiotic-only groups ( Zhang et al., 2020, Nat Commun). That pattern matches other trials and is one reason some brands pair berberine with probiotics, although PREMOTE did not show that the probiotics improved blood sugar results.

Low absorption is also why some products use dihydroberberine or other modified forms that are marketed as reaching the bloodstream more efficiently at lower doses. Those forms have less clinical outcome data than standard berberine. NLP-1 uses berberine at a conventional dose, which keeps it aligned with the bulk of the research. If you notice persistent stomach problems after two weeks, a lower dose split across meals, or stopping, is the sensible next step.

The "lose weight, even if you cheat" headline

SkinnyFit's landing page headline promises weight loss regardless of diet. No study of berberine, inulin, turmeric or probiotics supports that. In berberine trials, participants generally followed diet and lifestyle advice, and the average added weight effect was under a kilogram.

The trials in the berberine meta-analyses typically combined the supplement with lifestyle changes or compared it against them ( Dong et al., 2012, Evid Based Complement Alternat Med). The weight results that followed were real but small ( Elahi Vahed et al., 2026, Int J Obes). A supplement that produced weight loss without any change in eating would be a remarkable finding, and none of the ingredients in this formula has shown it.

Federal advertising rules expect health claims to be backed by competent and reliable scientific evidence, and weight-loss claims that promise results without diet or exercise have long been a focus of Federal Trade Commission enforcement. Whatever the legal position of a particular headline, buyers are better served by setting expectations from the trial data: a modest metabolic effect from berberine, added to the diet and activity changes that drive most weight loss.

If you are considering NLP-1 alongside a prescription GLP-1 drug, the gap is even larger. Prescription GLP-1 drugs produced weight changes in their trials that are many times what berberine has shown. Our GLP-1 weight loss overview covers what those trials found and who they are prescribed for.

Frequently asked questions

Is SkinnyFit NLP-1 the same as SkinnyFit GLP-1 Natural?

Yes. The current landing page uses NLP-1, and many retailers still list it as GLP-1 Natural Probiotic Supplement. The ingredient description matches.

Does it contain caffeine?

No. SkinnyFit states the formula is caffeine-free.

How long before berberine has an effect?

Trials measuring blood sugar and lipids usually ran 8 to 12 weeks or longer. Any weight change seen in meta-analyses was small and gradual.

Can I take it with metformin?

Only with your clinician's approval. Both lower blood sugar, and combining them without monitoring can lower it too much.

References

1. Zhang Y, Gu Y, Ren H, et al. Gut microbiome-related effects of berberine and probiotics on type 2 diabetes (the PREMOTE study). Nat Commun. 2020;11(1):5015. PubMed 33024120
2. Cani PD, Lecourt E, Dewulf EM, et al. Gut microbiota fermentation of prebiotics increases satietogenic and incretin gut peptide production with consequences for appetite sensation and glucose response after a meal. Am J Clin Nutr. 2009;90(5):1236-43. PubMed 19776140
3. Elahi Vahed I, Shahir-Roudi E, Nojumi S, et al. The effect of berberine on obesity indices: a systematic review and meta-analysis. Int J Obes (Lond). 2026;50(1):53-73. PubMed 41310257
4. Guo Y, Chen Y, Tan ZR, et al. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol. 2012;68(2):213-7. PubMed 21870106
5. Dong H, Wang N, Zhao L, et al. Berberine in the treatment of type 2 diabetes mellitus: a systemic review and meta-analysis. Evid Based Complement Alternat Med. 2012;2012:591654. PubMed 23118793
6. Asbaghi O, Ghanbari N, Shekari M, et al. The effect of berberine supplementation on obesity parameters, inflammation and liver function enzymes: A systematic review and meta-analysis of randomized controlled trials. Clin Nutr ESPEN. 2020;38:43-49. PubMed 32690176
7. Lu SS, Yu YL, Zhu HJ, et al. Berberine promotes glucagon-like peptide-1 (7-36) amide secretion in streptozotocin-induced diabetic rats. J Endocrinol. 2009;200(2):159-65. PubMed 18996945
8. Yu Y, Hao G, Zhang Q, et al. Berberine induces GLP-1 secretion through activation of bitter taste receptor pathways. Biochem Pharmacol. 2015;97(2):173-7. PubMed 26206195
9. Wang S, Ren H, Zhong H, et al. Combined berberine and probiotic treatment as an effective regimen for improving postprandial hyperlipidemia in type 2 diabetes patients: a double blinded placebo controlled randomized study. Gut Microbes. 2022;14(1):2003176. PubMed 34923903
10. Ye Z, Arumugam V, Haugabrooks E, et al. Soluble dietary fiber (Fibersol-2) decreased hunger and increased satiety hormones in humans when ingested with a meal. Nutr Res. 2015;35(5):393-400. PubMed 25823991
11. Depommier C, Everard A, Druart C, et al. Supplementation with Akkermansia muciniphila in overweight and obese human volunteers: a proof-of-concept exploratory study. Nat Med. 2019;25(7):1096-1103. PubMed 31263284
12. SkinnyFit product page. shop.skinnyfit.com