GlucoBerry Ingredients and Side Effects: A Dietitian’s Full Analysis

Bottom line up front: GlucoBerry is a four-ingredient blood sugar support supplement. Its formula is lean by design — Maqui Berry Extract (Delphinol®), Gymnema Sylvestre, Chromium Picolinate, and Biotin. Two of those ingredients (Maqui Berry and Gymnema) have genuine clinical evidence behind them at the doses used. Chromium is dosed at the low end of the studied range but is well-tolerated. Biotin sits at a nutritional rather than pharmacological dose, which limits what it can do. Side effects in healthy adults are minimal, but if you take any blood-sugar-lowering medication, Gymnema’s glucose-lowering activity is a real safety concern you need to discuss with your doctor before using this product.

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Home › GlucoBerry Review › GlucoBerry Ingredients

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TL;DR — Key Takeaways

• Core formula: 4 fully disclosed ingredients — no proprietary blends hiding weak doses
• Star ingredient: Delphinol® Maqui Berry at 180 mg — clinical trial data supports this exact dose for fasting glucose reduction
• Gymnema Sylvestre at 400 mg is within the clinically studied range and has the strongest track record among plant-based glucose support ingredients
• Chromium at 200 mcg is effective but on the lower end; Biotin at 300 mcg is a nutritional dose, not a pharmacological one
• Main caution: Do not combine with metformin, insulin, or other glucose-lowering drugs without physician oversight — Gymnema can potentiate their effects

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1. GlucoBerry Ingredient Panel — Overview

Before diving into the mechanism of each ingredient, here is the complete label at a glance, with doses compared against what clinical research has actually studied.

Ingredient	Claimed Dose	Clinical Range	Assessment
Maqui Berry Extract (Delphinol®)	180 mg	60–180 mg/day	At the top of the studied range — the exact dose used in the key RCT
Gymnema Sylvestre Leaf	400 mg	200–800 mg/day	Solidly within the therapeutic window
Chromium (as Chromium Picolinate)	200 mcg	200–1,000 mcg/day	Low end of studied range; well-tolerated
Biotin	300 mcg	100–10,000 mcg/day	Nutritional dose, not the pharmacological range used in metabolic research

What stands out immediately is that all four doses are disclosed. There is no proprietary blend obscuring how much of each ingredient you are actually getting. That transparency is worth noting — it allows an honest evaluation, which is what this article provides.

If you want my full evaluation of whether GlucoBerry is worth purchasing overall, including customer feedback and value assessment, read my complete GlucoBerry review. This article focuses exclusively on the science behind the formula.

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2. Maqui Berry Extract (Delphinol®) — The Star Ingredient

What It Is

Delphinol is a patented, standardized extract of Aristotelia chilensis — the Maqui Berry, native to Chilean Patagonia. The standardization is to a minimum of 35% delphinidins, a specific class of anthocyanin polyphenols that have been the subject of targeted blood sugar research. This is not generic Maqui Berry powder. The “standardized extract” distinction matters because raw berry powder has wildly variable polyphenol content.

The Clinical Evidence

The most relevant trial for GlucoBerry’s claims is a randomized, double-blind, placebo-controlled study published in 2016 by Del Campo and colleagues. In this trial, 45 overweight adults with mild hyperglycemia (elevated fasting glucose but not formally diabetic) received either 180 mg/day of Delphinol or placebo for 120 days. The Delphinol group saw a 5.3% reduction in fasting blood glucose compared to placebo, along with significantly improved postprandial (after-meal) glucose curves.

Full citation: Del Campo et al. (2016), Journal of Nutrition and Food Sciences. PubMed ID 26471215

The dose GlucoBerry uses — 180 mg — is the exact dose tested in that trial. This is clinically meaningful. Many supplements reference research conducted at doses three or ten times higher than what they actually put in the capsule. GlucoBerry does not do that here.

How It Works

Delphinol’s anthocyanins appear to work through multiple complementary pathways:

Intestinal glucose absorption: Delphinidins inhibit sodium-glucose cotransporter 1 (SGLT1) in intestinal cells, which is one of the primary mechanisms by which glucose enters the bloodstream after a meal. Inhibiting SGLT1 slows glucose uptake, blunting postprandial spikes. This is chemically analogous to how some pharmaceutical agents work, though the magnitude of inhibition from a plant extract is considerably smaller.

Alpha-glucosidase inhibition: Alpha-glucosidase is the intestinal enzyme that breaks down complex carbohydrates into simple sugars. Inhibiting this enzyme is the mechanism of action for the prescription drug acarbose (Precose). Maqui Berry anthocyanins have demonstrated alpha-glucosidase inhibitory activity in in vitro studies, though human trial data on this specific pathway remains limited.

Renal glucose handling (the “Blood Sugar Drain” mechanism): GlucoBerry’s marketing centers on the concept of supporting the kidney’s ability to excrete excess blood glucose via the “SG2” protein — referencing the renal SGLT2 pathway. Anthocyanins may support kidney filtration efficiency, though this mechanistic pathway is less directly supported by clinical data than the intestinal absorption mechanism. I would characterize this aspect of the marketing as biologically plausible but extrapolated beyond what the clinical evidence directly demonstrates.

Dose Verdict

180 mg of Delphinol daily is appropriate and matches the RCT. This is the strongest ingredient in the formula from an evidence standpoint.

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3. Gymnema Sylvestre — The Blood Sugar Workhorse

What It Is

Gymnema sylvestre is a woody climbing plant native to tropical India and Africa. Its Hindi name — Gurmar — translates to “sugar destroyer.” The leaves contain gymnemic acids, a class of triterpenoid saponins that interact with taste receptors for sweetness and with digestive and metabolic pathways for glucose handling. This is one of the most extensively researched botanical ingredients in blood sugar support.

The Clinical Evidence

The meta-analytic evidence on Gymnema is solid. A 2013 systematic review and meta-analysis by Pothuraju et al. evaluated multiple randomized controlled trials in patients with Type 2 diabetes and found that Gymnema supplementation reduced fasting blood glucose by approximately 11.1 mg/dL and HbA1c by approximately 0.9 percentage points compared to control conditions.

Full citation: Pothuraju et al. (2014), Journal of the Science of Food and Agriculture. PubMed ID 24353088

That 0.9% reduction in HbA1c is clinically meaningful — it approaches the efficacy of some first-line pharmaceutical agents in mild cases. The important caveat is that these trials were predominantly conducted in people who already had Type 2 diabetes. The evidence in pre-diabetic individuals or people with normal glucose metabolism is substantially weaker.

How It Works

Intestinal absorption blocking: Gymnemic acids share a molecular structure with glucose. They bind to intestinal glucose receptors, physically blocking glucose molecules from crossing the intestinal wall into the bloodstream. This reduces the glycemic impact of carbohydrate-containing meals.

Taste receptor interaction: The same molecular mimicry causes gymnemic acids to temporarily block sweet taste receptors on the tongue, reducing the perceived sweetness of sugar. While this sounds gimmicky, it has a legitimate behavioral benefit — it can reduce cravings for sweet foods by making them taste flat.

Pancreatic beta cell support: Animal studies and some human research suggest that Gymnema may support the regeneration or protection of insulin-producing beta cells in the pancreas. This is a compelling mechanism, though the human evidence is less definitive than the intestinal absorption data.

Insulin secretion: Some trials suggest Gymnema increases insulin secretion from the pancreas, which would contribute to glucose clearance after meals.

Dose Verdict

At 400 mg/day, GlucoBerry’s Gymnema Sylvestre dose is solidly within the 200–800 mg/day range used in clinical research. This is an appropriate and effective dose for most adults. If you want to read more about how Gymnema compares to other blood sugar ingredients like berberine, see my guide to berberine for blood sugar.

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4. Chromium Picolinate — Insulin Cofactor

What It Is

Chromium is an essential trace mineral required in microgram quantities. As Chromium Picolinate, it is bound to picolinic acid to enhance intestinal absorption — Chromium Picolinate has significantly higher bioavailability than chromium chloride, the form used in cheaper supplements.

Chromium’s role in blood sugar regulation centers on a molecule called chromodulin (also known as Low Molecular Weight Chromium-Binding Substance, or LMWCr). Chromodulin binds to the insulin receptor after chromium is released from storage, amplifying the receptor’s sensitivity to insulin signaling. In practical terms, chromium helps your cells respond more effectively to the insulin your pancreas already produces.

The Clinical Evidence

A comprehensive meta-analysis published in 2015 by Suksomboon et al. analyzed 42 randomized controlled trials of chromium supplementation. The pooled analysis found that chromium significantly reduced fasting blood glucose and HbA1c compared to placebo, with the largest effects seen in individuals who already had elevated glucose. Effects in normoglycemic individuals were smaller.

Full citation: Suksomboon et al. (2015), PLOS ONE. PubMed ID 26202346

The meta-analysis included trials using doses ranging from 200 to 1,000 mcg/day. GlucoBerry uses 200 mcg, which is at the low end of that studied range. It is not an inadequate dose — 200 mcg is where meaningful effects begin to appear — but the dose-response data suggests larger effects at higher doses in the 400–600 mcg range.

Safety at 200 mcg

The US Food and Nutrition Board has not established a formal Tolerable Upper Intake Level for chromium due to its low toxicity profile. The Adequate Intake is set at 25–35 mcg/day, meaning 200 mcg is a supplemental dose approximately 6–8x the Adequate Intake. This is well within what research demonstrates to be safe. Studies using 400–1,000 mcg/day over extended periods have not shown meaningful adverse events in healthy adults.

One safety note: very high doses of chromium (above 1,000 mcg/day over long periods) have been associated with potential kidney and liver concerns in isolated case reports, though these are rare and typically involve picolinate forms at very high doses. At 200 mcg, this is not a concern.

Dose Verdict

200 mcg is appropriate and safe. It sits at the low end of the therapeutic range, which means some users might see more pronounced effects at a higher dose, but it is not ineffective at this level.

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5. Biotin — Supporting Role

What It Is

Biotin (vitamin B7) is a water-soluble B vitamin essential for carbohydrate, fat, and protein metabolism. It serves as a cofactor for several carboxylase enzymes involved in energy metabolism. The connection to blood sugar specifically comes from its role in activating glucokinase — an enzyme in the pancreas and liver that acts as a glucose sensor and regulates glucose metabolism.

The Dose Reality Check

This is where I need to be honest about a meaningful gap in GlucoBerry’s formula.

Research on biotin’s metabolic effects — specifically the glucokinase activation mechanism — has been conducted primarily at pharmacological doses of 2,000 to 10,000 mcg/day. GlucoBerry provides 300 mcg of biotin, which is 2% of the daily value and falls squarely in the nutritional supplementation range rather than the pharmacological range.

The relevant research: Valdez-Solana et al. and earlier work by Romero-Navarro et al. demonstrated that biotin at high doses activates glucokinase gene expression in the pancreas. PubMed reference: Romero-Navarro et al., 1999

At 300 mcg, it is unlikely that biotin contributes meaningfully to GlucoBerry’s blood sugar effects. That said, biotin at 300 mcg is beneficial for hair, skin, and nail health — and at this dose, it is essentially a nutritional safety net for individuals with borderline biotin insufficiency, which can be more common in people with metabolic conditions.

This is not a formula-killing flaw. Biotin at nutritional doses causes no harm and provides some nutritional value. But I am not going to overstate what 300 mcg of biotin is doing in the context of this formula’s blood sugar claims.

Dose Verdict

Fine as a nutritional inclusion; not contributing meaningfully to the formula’s core blood sugar mechanism at 300 mcg.

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6. GlucoBerry Side Effects: What to Watch For

The overall side effect profile of GlucoBerry is favorable, but “generally safe” does not mean “safe for everyone in every context.” Here is an ingredient-by-ingredient breakdown.

Maqui Berry Extract (Delphinol®) — Side Effects

Delphinol at 180 mg/day has been evaluated in published clinical trials without significant adverse events reported. Anthocyanins from berry sources are well-tolerated across populations. Potential mild side effects that may occur with any polyphenol-rich extract include:

• Mild gastrointestinal upset (nausea, loose stool) in sensitive individuals, particularly when taken on an empty stomach
• Very rarely, mild headache during the initial days of use — likely unrelated to the ingredient itself

No serious adverse events attributable to Delphinol at 180 mg/day have been documented in the peer-reviewed literature.

Gymnema Sylvestre — Side Effects

Gymnema’s side effect profile is more clinically relevant than Maqui Berry’s, primarily because of its glucose-lowering potency:

• Hypoglycemia risk (serious): In individuals taking insulin, metformin, sulfonylureas, or other blood-sugar-lowering medications, Gymnema’s additive effect on glucose reduction can cause blood sugar to drop dangerously low. This is not theoretical — it is a pharmacologically plausible and documented drug-herb interaction.
• Taste alteration: Gymnemic acids temporarily reduce sweet taste perception. This is a feature for some users (reduced sugar cravings) and a side effect for others. It is temporary and dose-dependent.
• Mild gastrointestinal effects: Some users report mild nausea, particularly during the first week of use. Taking Gymnema with food reduces this risk.
• Headache: Reported by a subset of users in some trials, possibly related to the taste alteration effect or mild glucose fluctuation.

Chromium Picolinate — Side Effects

At 200 mcg daily, Chromium Picolinate is well-tolerated by most people. Reported side effects at supplemental doses are rare and generally mild:

• Very rarely: headache, nausea, or mood changes at higher doses (not typically at 200 mcg)
• Potential interaction with antacids, proton pump inhibitors (PPIs), or H2 blockers, which can reduce chromium absorption
• Rare anecdotal reports of sleep disturbance or vivid dreams, though this has not been consistently documented in controlled trials

Biotin — Side Effects

Biotin at 300 mcg daily is essentially without adverse effects. Biotin is water-soluble and excess is excreted in urine. The only notable concern with biotin is its potential to interfere with certain laboratory tests — including thyroid function tests and cardiac troponin assays — because biotin can interfere with the biotin-streptavidin binding mechanism used in some immunoassays. At 300 mcg, this is unlikely to produce clinically significant interference, but if you are scheduled for blood tests, it is worth informing your physician that you take biotin.

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7. Drug Interactions and Safety Considerations

This section addresses the most clinically significant interactions. This is not boilerplate — these are real considerations that should inform your decision.

Gymnema + Blood Sugar Medications (HIGH PRIORITY)

Gymnema Sylvestre has documented blood-glucose-lowering activity. When combined with:

• Metformin (Glucophage)
• Sulfonylureas (glipizide, glimepiride, glyburide)
• Insulin (any form)
• SGLT2 inhibitors (empagliflozin, canagliflozin, dapagliflozin)
• DPP-4 inhibitors (sitagliptin, saxagliptin)
• GLP-1 receptor agonists (semaglutide/Ozempic, liraglutide)

…the combined effect could lower blood glucose further than either agent alone. In people with tightly controlled diabetes, this can produce hypoglycemia (blood sugar dangerously low), which causes symptoms including dizziness, confusion, sweating, shakiness, and in severe cases, loss of consciousness.

If you take any diabetes medication, do not use GlucoBerry without explicit guidance from your prescribing physician. I am not including this warning because it is legally required — I am including it because it is medically real.

Chromium + Medications That Affect Absorption

• Antacids, PPIs, H2 blockers: These can reduce chromium absorption by altering gastric pH. Take GlucoBerry at least 2 hours apart from acid-reducing medications.
• NSAIDs (ibuprofen, naproxen): Some evidence suggests NSAIDs may increase chromium absorption. This is unlikely to cause problems at 200 mcg, but worth noting for frequent NSAID users.
• Thyroid medications (levothyroxine): Chromium may reduce absorption of thyroid medications. Take at least 4 hours apart.

Maqui Berry + Anticoagulants

High-polyphenol plant extracts can theoretically have mild antiplatelet activity. At 180 mg of Delphinol, this effect is modest and unlikely to be clinically significant, but individuals on warfarin (Coumadin), clopidogrel (Plavix), or other anticoagulants should mention Maqui Berry supplementation to their physician.

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8. Who Should Avoid GlucoBerry?

Based on the ingredient analysis above, GlucoBerry is not appropriate for:

• Anyone currently managing diabetes with prescription medication (unless cleared by their physician — see drug interaction section)
• Pregnant or breastfeeding women — there is insufficient safety data on Gymnema and Delphinol in pregnancy
• Children and adolescents — the formula is not studied in pediatric populations
• Anyone scheduled for surgery within 2 weeks — Gymnema’s glucose-lowering effect creates unpredictability during surgical fasting and anesthesia
• People with known low blood sugar (hypoglycemia) — Gymnema could worsen this condition

GlucoBerry is designed for healthy adults with blood sugar already within the normal range who are looking for nutritional support for glucose metabolism, not a replacement for medical management of diagnosed metabolic conditions.

For more on who this product is and is not suited for, read my article on whether GlucoBerry really works.

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9. How GlucoBerry’s Ingredient Doses Compare to Competitors

The blood sugar supplement market is crowded. A common industry tactic is to list 15–20 ingredients in a “proprietary blend,” making the formula look impressive while hiding that each ingredient is included at a sub-therapeutic dose. GlucoBerry takes the opposite approach.

Here is how GlucoBerry’s formula compares to common competitor approaches:

Feature	GlucoBerry	Typical Competitor Formula
Number of ingredients	4	10–20+
Doses disclosed	Yes (all)	Often hidden in proprietary blends
Delphinol® included	Yes (180 mg)	Rarely; generic maqui berry more common
Gymnema dose	400 mg	Ranges from 50 mg (underdosed) to 800 mg
Chromium included	Yes (200 mcg)	Common, but often as chromium chloride (lower bioavailability)
Berberine included	No	Common in “kitchen sink” formulas

The notable absence from GlucoBerry is berberine — arguably the most clinically studied botanical glucose support agent, with a mechanism of action similar to metformin (AMPK activation). Berberine’s absence is consistent with GlucoBerry’s positioning around its proprietary Delphinol-centered “Blood Sugar Drain” mechanism. If berberine is something you are specifically interested in, I cover the evidence in my guide to berberine for blood sugar.

For a broader comparison across leading blood sugar supplement formulas and what the ingredient evidence actually supports, see my guide to the best blood sugar supplement ingredients.

I also compare GlucoBerry against a close competitor in my article on GlucoBerry vs SugarMute — that article examines how the two formulas differ at the ingredient level and who each one is better suited for.

For a look at a structurally different blood sugar formula, my Gluco6 review breaks down an ingredient panel built around a different mechanistic approach.

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10. The Honest Verdict: Does the Formula Hold Up?

After analyzing each ingredient against the clinical literature, here is where I land:

GlucoBerry’s formula is scientifically credible at its core, with one honest caveat about biotin.

Maqui Berry as Delphinol® at 180 mg is the formula’s strongest claim — this is a patented, standardized extract used at the exact dose that produced a statistically significant 5.3% fasting glucose reduction in a published RCT. That is a real result at a real dose.

Gymnema Sylvestre at 400 mg has the deepest evidence base of any botanical glucose support ingredient — decades of research, multiple meta-analyses, and a well-understood mechanism of action. The 400 mg dose sits comfortably within the therapeutic window.

Chromium Picolinate at 200 mcg is well-evidenced and well-tolerated. A higher dose (400–600 mcg) might produce more pronounced effects for some users, but 200 mcg is not ineffective.

Biotin at 300 mcg is where I have to be direct: this dose is at the nutritional level, not the pharmacological range used in metabolic research. It is not harmful and provides B-vitamin nutritional value, but it is not meaningfully contributing to the blood sugar support mechanism at 300 mcg.

The net assessment: two strong ingredients at appropriate doses, one decent-but-low-end ingredient, and one that is more nutritional filler than active agent. That is a better score than most competitors, which often have five weak ingredients for every one strong one.

If the formula is curious to you but you are still on the fence, my full GlucoBerry review covers the complete picture — pricing, customer feedback, where it falls short, and who it is most likely to help. I also address the common question of whether GlucoBerry is legitimate or a scam with the same ingredient-level rigor.

To understand current pricing and any available discount offers, see my GlucoBerry pricing guide.

For real-world user experiences that go beyond the marketing page, see my roundup of GlucoBerry real reviews.

This analysis was prepared independently. My team at Shelf Insider — learn more about us — has no relationship with the manufacturer. I evaluate the ingredient science first and present my honest assessment regardless of outcome.

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11. Frequently Asked Questions

What are the ingredients in GlucoBerry?

GlucoBerry contains four ingredients: Maqui Berry Extract as Delphinol® (180 mg), Gymnema Sylvestre Leaf (400 mg), Chromium as Chromium Picolinate (200 mcg), and Biotin (300 mcg). The formula is notably lean compared to competitors, focusing on a small number of research-backed ingredients rather than a large proprietary blend.

Does GlucoBerry have side effects?

GlucoBerry’s ingredients are generally well-tolerated in healthy adults at the stated doses. The primary safety consideration is the potential for Gymnema Sylvestre to enhance blood-glucose-lowering medications, creating a hypoglycemia risk. Chromium Picolinate at 200 mcg is safe for most people. Maqui Berry anthocyanins at 180 mg are well-tolerated in published trials with no serious adverse events reported. See Section 6 above for a full ingredient-by-ingredient breakdown.

What is Delphinol and how does it affect blood sugar?

Delphinol is a standardized Maqui Berry extract standardized to 35% delphinidins, a class of anthocyanins. In a randomized controlled trial, 180 mg/day of Delphinol for 120 days reduced fasting blood glucose by approximately 5.3% and improved postprandial glucose control in overweight adults. Its mechanisms include reducing intestinal glucose absorption, inhibiting alpha-glucosidase enzymes, and supporting renal glucose excretion pathways.

Is the Gymnema dose in GlucoBerry effective?

GlucoBerry’s Gymnema Sylvestre dose of 400 mg/day falls within the range used in clinical trials, which typically test 200–800 mg/day. Meta-analyses suggest Gymnema can reduce fasting blood glucose by approximately 11.1 mg/dL and HbA1c by 0.9% in people with Type 2 diabetes. Effects in pre-diabetic or healthy adults are less well-studied but plausible given the mechanism.

Can I take GlucoBerry if I’m on metformin or other diabetes drugs?

Do not take GlucoBerry while on diabetes medications without first consulting your physician. Gymnema Sylvestre can potentiate blood-sugar-lowering effects, and combining it with metformin or other hypoglycemics could cause blood sugar to drop dangerously low. This is a genuine pharmacological concern, not routine boilerplate. See Section 7 for the full drug interaction breakdown.

Is Chromium Picolinate safe at 200 mcg?

Yes. The Tolerable Upper Intake Level for chromium has not been formally established due to its low toxicity profile. 200 mcg daily is well within the range used in research, which extends up to 1,000 mcg in studies. The bioavailability of Chromium Picolinate is higher than other chromium forms. No significant adverse effects are reported at 200–400 mcg/day.

Does GlucoBerry contain any allergens or stimulants?

GlucoBerry does not contain caffeine, stimulants, or common allergens in its active ingredient list. The product is manufactured in an FDA-registered GMP facility. Capsule shell ingredients and excipients are not detailed in publicly available marketing materials — those with severe allergies should contact the manufacturer directly before purchasing.

Why does GlucoBerry have only 4 ingredients?

The streamlined formula reflects a deliberate positioning around its core mechanism — Delphinol’s “Blood Sugar Drain” activity — rather than a multi-ingredient approach. Fewer ingredients also means lower proprietary blend risk, as all doses are disclosed and can be evaluated against the research. Whether four ingredients are sufficient depends on whether your needs align with what these four specifically address.

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For additional context on this formula and who it is best suited for, read my full GlucoBerry for blood sugar overview.

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Disclaimer: 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. Individual results may vary. Consult a qualified healthcare provider before starting any supplement regimen, especially if you have a medical condition or take prescription medications.