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This article is for informational purposes only and isn’t medical advice. Talk to a doctor or pharmacist before starting any weight-management supplement, especially if you take prescription medication or manage an existing health condition.
Updated August 2026: Re-verified every price in this audit against current manufacturer and major-retailer listings. NOW Foods Glucomannan’s real-world price has dropped substantially since our last check — from roughly $27 to about $16.50 for the same 180-capsule bottle at two independent retailers — which only strengthens its position as the cheapest option here. PhenQ, Hydroxycut Original, and Zantrex Black priced out within a few cents of our previous figures, so those numbers stand. We also restructured this piece into a single upfront scorecard so you can see every claim against every finding before reading a word of our commentary.
An audit is supposed to end with a clean pass or fail. Ours doesn’t. The scorecard below checks five real, currently-sold OTC appetite suppressants — their exact label claims, what independent evidence actually found, whether the labeled dose matches the dose that was studied, and each product’s real FDA and regulatory status — side by side, before we interpret any of it. Read the table first; the commentary underneath just walks you through what each column means and why it matters.
Table of Contents
- The Audit: Claim vs. Evidence vs. Regulatory Status
- Reading the Table, Column by Column
- Deeper Detail on Each of the 5 Products
- Real Cost Per Month at the Labeled Dose
- How We Compared
- FAQ
The Audit: Claim vs. Evidence vs. Regulatory Status
We picked five real, currently-sold, non-prescription products that represent the main approaches on the market: a single-ingredient fiber capsule, a multi-ingredient stimulant stack, a legacy thermogenic brand, an herbal blend with its own published research, and a proprietary-blend softgel. None of these are GLP-1 medications or require a prescription. Every claim below is drawn from each product’s own current label or marketing copy; every evidence and regulatory finding is sourced to an independent study, database, or the FDA’s own guidance, cited in the deeper sections further down the page.
| Product | What the Label Claims | What Independent Evidence Shows | Labeled Dose vs. Studied Dose | FDA / Regulatory Status |
|---|---|---|---|---|
| NOW Foods Glucomannan | “Supports regularity” and “healthy weight management” via konjac-root fiber | Pooled 8-RCT meta-analysis found −0.22 kg vs. placebo — not statistically significant | ~3.45 g/day labeled vs. ~2–4 g/day studied — roughly in range, but the pooled result was still null | Dietary supplement; not FDA-approved or reviewed before sale; no recall history found |
| Zotrim | Herbal blend marketed to “reduce appetite and slow eating speed” | 6-week, 73-person open-label study (no placebo, no blinding) reported significant self-reported weight/waist reductions | Matches by definition — same finished product, same dose used in its own trial | Dietary supplement; not FDA-approved or reviewed before sale; no recall history found |
| PhenQ | Multi-ingredient “fat burner” built around a patented α-Lacys Reset blend | Independent ingredient review found ~25 mg alpha-lipoic acid — a fraction of the 600–1,200 mg/day used in studies showing any effect | Alpha-lipoic acid far below studied amount; caffeine (~150 mg/day) in typical research range | Dietary supplement; not FDA-approved or reviewed before sale; no recall history found |
| Hydroxycut Original | “Metabolism and energy support” from 200 mg caffeine, green coffee bean extract, and apple cider vinegar | NIH’s LiverTox database documents a 2009 recall and roughly 50 subsequent liver-injury cases tracked in reformulated products | Caffeine dose disclosed and in typical thermogenic range, but the labeled daily max (400 mg) is the FDA’s entire daily ceiling before any other source | Dietary supplement; not FDA-approved. Documented FDA-related recall (2009, following a 2004 ephedra-formula ban) and continued post-recall adverse-event reports per NIH LiverTox |
| Zantrex Black | “High-velocity” energy and weight-management support from a 1,160 mg proprietary blend | Label discloses only the combined blend weight, not individual ingredient amounts; no independent finished-product study found | Caffeine content within the blend is undisclosed and cannot be checked against any published safety guidance | Dietary supplement; not FDA-approved or reviewed before sale; no recall history found, but the blend’s opacity means its stimulant load can’t be independently verified |
Reading the Table, Column by Column
The claims column: every label in this audit leans on the same rhetorical move — “supports,” “management,” “energy,” language that implies an outcome without promising one. That’s not an accident; it’s the legal difference between a supplement claim and a drug claim. None of the five labels state a specific, guaranteed amount of weight loss, and that’s appropriate, because none of the evidence below would support one.
The evidence column: only one product here — Zotrim — has a trial on the actual finished formula, and even that trial has no placebo group and no blinding, so treat it as a real but limited signal, not proof. The most-studied single ingredient in the category, glucomannan, has the most rigorous evidence base (a pooled meta-analysis of multiple RCTs) and it’s also the one with the clearest negative result. PhenQ’s evidence problem isn’t that alpha-lipoic acid has zero research behind it — it’s that the label’s dose is nowhere near the dose that research used. Zantrex Black’s evidence column is empty by design: a proprietary blend that hides individual amounts can’t be evidence-checked at all.
The dose-match column: this is where marketing and reality diverge most sharply. A “clinically studied ingredient” claim only means something if the product delivers a dose close to what was actually tested — PhenQ’s alpha-lipoic acid content fails that test badly, while glucomannan and PhenQ’s own caffeine content pass it. Zantrex Black can’t even be evaluated on this axis, which we consider a mark against it, not a neutral unknown.
The FDA/regulatory column: read this one first if you read nothing else. By statute, the FDA does not review or approve dietary supplements for safety or effectiveness before they reach a shelf, according to the FDA’s own consumer guidance on what “FDA approved” actually means — so every product in this table starts from the same baseline of zero pre-market FDA review. What differs is post-market history: four of the five products have no recall or safety-action history we could find, and one — Hydroxycut — has a documented one. That’s a materially different risk profile, and it’s the single most important fact in this entire audit.
Deeper Detail on Each of the 5 Products
1. NOW Foods Glucomannan (Konjac Root) 575 mg
Glucomannan is a soluble fiber derived from konjac root that expands in the stomach when taken with water before a meal. It’s the single most-studied ingredient in this category, which makes its result the most sobering: a systematic review and meta-analysis of randomized controlled trials, summarized in the NIH’s National Library of Medicine database of reviews of effects, pooled eight RCTs and found a weight-loss difference of just −0.22 kg versus placebo — not statistically significant. The reviewers concluded the available trial evidence “does not show that glucomannan intake generates statistically significant weight loss.” The label isn’t lying about what glucomannan is; it’s just not backed by the research the way the “weight management” framing implies.
Pros: Now the cheapest option here by an even wider margin than before; single disclosed ingredient at a dose close to what trials actually used; no caffeine or stimulants; widely available.
Cons: The best available evidence found no significant weight-loss effect; common side effects include bloating, gas, and diarrhea; must be taken with a full glass of water or it can swell before swallowing and pose a choking/blockage risk, per the product’s own label warning.
Best for: People who want to try the most-studied ingredient in the category without adding stimulants, and who are comfortable with a modest-to-no expected weight effect.
2. Zotrim
Zotrim is unusual in this category because the company has funded small human trials on the actual finished product rather than just pointing to studies on individual ingredients elsewhere. A study published through the University of Manchester’s research group and summarized in its institutional research repository followed 73 overweight participants for six weeks and reported statistically significant reductions in self-reported weight and waist circumference, with about 22% of participants reaching a “clinically significant” weight loss. That’s real evidence — but it’s also industry-linked, uncontrolled (no placebo group, no blinding), and short.
Pros: Rare among this list for having trials on the finished product, not just individual ingredients; contains B-vitamins alongside the herbal blend; moderate caffeine load compared with dedicated thermogenics.
Cons: The available trials are small, short, uncontrolled, and manufacturer-linked; still contains caffeine, which stacks with coffee, tea, and other supplements.
Best for: People who want the most direct (if imperfect) evidence trail among OTC options and don’t mind a herbal-stimulant profile.
3. PhenQ
PhenQ is a multi-ingredient stack built around a patented blend called α-Lacys Reset, plus Capsimax (cayenne pepper extract), caffeine, chromium picolinate, L-carnitine, and nopal cactus fiber. Several individual ingredients have some human research behind them at specific doses, but an independent ingredient-and-label review by WellnessVerge found PhenQ’s proprietary blend delivers roughly 25 mg of alpha-lipoic acid — a fraction of the 600–1,200 mg per day used in the studies that show any weight-related effect for that compound.
Pros: Reasonable caffeine dose relative to research; combines a fiber source (nopal) with stimulant ingredients; no single mega-dose stimulant spike.
Cons: Several proprietary-blend ingredients appear at a fraction of studied amounts; highest price per month of any product in this audit; no independent third-party testing disclosed.
Best for: People who want an all-in-one stack and are willing to pay a premium for convenience, understanding the underlying doses are mostly unproven at label strength.
4. Hydroxycut Original
Hydroxycut has the longest and most complicated regulatory history in this audit. The FDA banned the original ephedra-based formula in 2004 over cardiovascular risk, then recalled all Hydroxycut products in 2009 after receiving reports of roughly two dozen liver-injury cases, including one death. According to the NIH’s LiverTox database, the products were reformulated after the recall, but “Hydroxycut products with different ingredients are still commercially available and have continued to be implicated in cases of clinically apparent acute liver injury” — with roughly 50 documented cases tracked since.
Pros: Exact caffeine dose stated on the label (200 mg/serving); widely available at mainstream retail; relatively inexpensive per bottle.
Cons: Brand has a documented FDA recall history and continued post-recall liver-injury reports per NIH LiverTox; a full labeled day’s dose (4 capsules) delivers about 400 mg of caffeine, the FDA’s entire daily ceiling before counting coffee or anything else; true monthly cost is higher than the sticker price suggests (see the cost table below).
Best for: People who specifically want a disclosed, verifiable caffeine dose and who have discussed the brand’s safety history with a doctor first — not a starting point for anyone with liver risk factors.
5. Zantrex Black
This is the least transparent label in our audit. Zantrex Black’s supplement facts panel discloses a single combined weight for its entire 12-ingredient proprietary blend — 1,160 mg — without breaking out how much of that is actual caffeine versus filler botanicals. That means there’s no way to check the product’s caffeine content against the FDA’s general guidance that 400 milligrams a day is not generally associated with negative effects for a healthy adult, because you don’t actually know how much caffeine you’re taking.
Pros: Widely stocked at mainstream pharmacy chains; familiar, long-standing product line; contains a mix of stimulant botanicals rather than isolated synthetic caffeine.
Cons: Proprietary blend hides the actual caffeine dose, so it can’t be checked against any published safety guidance; highest true monthly cost of any product here once you account for the labeled 3-times-daily dosing; no finished-product clinical trials disclosed.
Best for: Almost no one, honestly — if you specifically want a stimulant-based option, Hydroxycut Original at least tells you the caffeine dose you’re taking; Zantrex Black doesn’t.
Real Cost Per Month at the Labeled Dose
Sticker price is misleading in this category because “servings per day” varies so much between products. We calculated true monthly cost using each product’s own labeled directions for use — not the minimum dose, and not our own guess. NOW Foods Glucomannan’s price dropped substantially since we last checked; the other four priced out within a few cents of our earlier figures.
| Product | Bottle price | Contents | Labeled daily dose | Days per bottle | True cost per month |
|---|---|---|---|---|---|
| NOW Foods Glucomannan | $16.52 | 180 capsules | 6 capsules (2 servings) | 30 days | ~$16.52 |
| Zotrim | $69.99 | 180 tablets | 6 tablets | 30 days | ~$69.99 |
| PhenQ | $69.99 | 60 capsules | 2 capsules | 30 days | ~$69.99 |
| Hydroxycut Original | $26.99 | 72 capsules | 4 capsules (label max) | ~18 days | ~$44.98 |
| Zantrex Black | $29.99 | 84 softgels | 6 softgels (label max) | ~14 days | ~$64.26 |
The takeaway: Hydroxycut Original and Zantrex Black look like the cheapest products on the shelf, but once you follow their own labeled directions, both end up costing more per month than Zotrim or PhenQ — and NOW Foods Glucomannan is now cheaper than every other option here by a wider margin than it was previously.
Prices are approximate, current as of publication, and change frequently — confirm the latest price with the retailer before buying.
Common Ingredients: What the Research Actually Supports
Three ingredients show up across most of this category, so it’s worth separating what’s documented from what’s marketing shorthand.
Glucomannan: the best-studied appetite ingredient on this list, and the one with the clearest negative finding — the pooled RCT data found no statistically significant weight-loss effect versus placebo. Caffeine: reliably suppresses appetite modestly and short-term, which is why it appears in some form in four of the five products here — but tolerance builds quickly, and the FDA’s general 400 mg/day guidance leaves little room for stacking a supplement on top of normal coffee or tea intake. Yerba mate/guarana/damiana blends: mostly studied together as finished products (like Zotrim) rather than as isolated compounds, which makes it hard to know which ingredient, if any, is doing the work.
How We Compared
This audit is based on a verified evidence review, not hands-on product testing — we did not personally use these supplements. For each product, we pulled the current supplement facts label from the manufacturer or a major retailer this month, cross-checked ingredient doses against peer-reviewed research and systematic reviews where available, and checked each brand’s FDA and regulatory history through public databases including NIH’s LiverTox and the FDA’s own consumer guidance. Pricing was collected from manufacturer and major retail listings this month; each figure was checked against at least one additional independent retailer where possible. For more on how we source, verify, and disclose our methodology, see our editorial standards.
For related reading, we’ve also compared fiber supplements by fermentability and cost per gram, run the math on meal-replacement shakes for a weight-management plan, and priced out prepared-meal delivery services built around weight loss.
FAQ
What’s the single most important thing this audit found?
That “not FDA-approved” applies equally to all five products, but “documented FDA recall history” applies to only one of them — Hydroxycut. Those are two very different facts, and conflating them is the biggest mistake a shopper in this category can make.
Has any product or ingredient here actually received FDA approval?
No. None of the five products are drugs, and the FDA does not review or approve dietary supplements for safety or effectiveness before they’re sold. What the FDA has done is take direct regulatory action against one brand in this audit: it banned Hydroxycut’s original ephedra formula in 2004 and the products were recalled in 2009. That’s an enforcement action, not an approval — the two are not interchangeable, and no product here should be described as “FDA approved.”
Which ingredient came out worst in the evidence column?
Glucomannan has the strongest evidence base of any ingredient here — a pooled analysis of multiple randomized trials — and that analysis still found no statistically significant weight-loss effect. PhenQ’s alpha-lipoic acid content fares worse in a different way: the research on that compound is more promising, but PhenQ’s own label delivers a small fraction of the dose that research used.
Is Zantrex Black’s proprietary blend a dealbreaker?
We think it should factor heavily into your decision. A proprietary blend that lists only a combined ingredient weight means you can’t verify how much caffeine or any other single ingredient you’re actually consuming, which makes it impossible to check against published safety guidance like the FDA’s 400 mg/day caffeine note.
What changed in the cost numbers since this audit was first published?
NOW Foods Glucomannan got noticeably cheaper — down to about $16.52 for the same 180-capsule bottle at two independent retailers we checked, from roughly $27 previously — which widens its lead as the least expensive option in this category. The other four products priced out within a few cents of our earlier figures.
Can I combine one of these with a prescription weight-loss medication?
This audit can’t answer that for your specific situation. Talk to a doctor or pharmacist before combining any OTC supplement with prescription medication, existing health conditions, or other supplements.
