Koi CBD Review – The Weight-Loss Gummy Has 1/50th the Studied ACV Dose

Koi has been selling CBD since 2015 and now runs one of the widest novel-cannabinoid ranges in the market — delta-8, delta-9, delta-10, HHC, THC-O, THC-P, THCA and THCV. Two of those matter here. The THCV + ACV gummies are marketed around appetite control, which makes them directly relevant to readers of this site — and the apple cider vinegar in them is roughly one fiftieth of the amount used in the research. And Koi still sells THC-O, which produces a potent lung toxicant when vaped.

The THCV + ACV Gummy: Doing the Arithmetic

This is the product we care most about, because it is aimed at exactly the reader this site serves. Here is what is in it.

A jar holds 20 gummies, 200mg of THCV in total, with folic acid and vitamin B12 also listed. Suggested use is one gummy every six hours as needed.

The Apple Cider Vinegar Is About One Fiftieth of the Studied Dose

And the 30ml figure is itself the optimistic end of a contested literature. The Mayo Clinic’s position is that apple cider vinegar is not likely to cause weight loss and that research has not proved that it does. A review of 13 human studies concluded there was not enough evidence. Some meta-analysis does report modest reductions in waist circumference, BMI and body weight, particularly in people with obesity or type 2 diabetes — so it is not nothing, but it is small and disputed even at full dose.

Put those together and the conclusion is unavoidable: the ACV in these gummies is doing marketing work, not physiological work. This is not a Koi-specific failing — it is close to universal across the ACV gummy category, where the amount of vinegar that fits in a palatable sweet is nowhere near what the studies used. But it is the reason we would not buy this product for the reason its name suggests.

One incidental point in the gummies’ favour: undiluted apple cider vinegar is acidic enough to damage tooth enamel and irritate the oesophagus, which is a genuine problem with the drink-a-shot approach. A gummy avoids that. It also avoids delivering a meaningful dose.

What THCV Actually Does, and the Drug That Came Before It

THCV is the genuinely interesting half of this product, and it deserves a fair hearing.

Unlike THC — which is an FDA-approved appetite stimulant — THCV acts as an antagonist at the CB1 receptor, blocking the receptor THC activates. That is a plausible mechanism for reduced appetite rather than a marketing story. A 2025 study in the journal Cannabis gave obese adults daily oral strips and reported that the high-dose group — 16mg THCV with 20mg CBD — lost an average of 4.1kg over 90 days, with reductions also recorded in abdominal girth, systolic blood pressure and LDL cholesterol.

Three things to hold alongside that. It is a small trial, and the field needs larger ones before anything is settled. The dose does not match — a Koi gummy is 10mg THCV with no CBD, while the label’s one-every-six-hours maximum reaches 40mg a day, so neither a single gummy nor the maximum corresponds to the combination that was studied. And 4.1kg over 90 days is modest against what prescribed GLP-1 medications achieve in large randomised trials. If you are on one, this is not a substitute — and nothing here is a reason to change a prescribed treatment.

THC-O: Schedule I According to the DEA, and Ketene When Vaped

Koi’s range includes THC-O, and this is the most serious safety item in the review.

On legality, the position is genuinely contested. In a letter dated 13 February 2023, the DEA stated that delta-8 and delta-9 THC-O acetate are Schedule I controlled substances, because they do not occur naturally in the cannabis plant and meet the definition of tetrahydrocannabinols. The US Court of Appeals for the Fourth Circuit subsequently ruled that THC-O acetate does meet the legal definition of hemp under the 2018 Farm Bill, contradicting the DEA. We are not going to tell you which will prevail.

We covered EVALI in our PAX review and concluded the lesson was about supply chain — buy from licensed sources. THC-O is a different case: here the risk is in the molecule itself when heated, not in who filled the cartridge. We would not vape THC-O, and we would not recommend anyone else does. If you want the compound in some other form, that is a decision to make knowing the legal position is disputed; the vaping question, in our view, is not close.

The Regulatory and Testing Record

Koi has been trading since 2015, which is a long run in this industry, and it publishes certificates of analysis. Three items belong in the picture, presented with their dates.

In 2019, Koi received an FDA warning letter concerning branding products as dietary supplements or drugs and making claims about them. The same year it was named in a class action alleging fraud; that case was dismissed in 2020. Seven years is a considerable time and companies change — we report this as history, not as a current finding. It is relevant context nonetheless for a brand now selling a product marketed around appetite control.

On testing, independent CBD review coverage raises three specific concerns:

• Some certificates appear outdated rather than current.
• Some products advertised as broad spectrum appear to contain only pure CBD — a labelling accuracy problem, since broad spectrum should retain minor cannabinoids and terpenes.
• Solvents have reportedly been detected in products whose marketing claims CO2 extraction — and CO2 extraction is marketed specifically on the basis that it avoids solvents.

We have not verified those findings ourselves and they come from review sites rather than a formal audit, so treat them as flags rather than conclusions. But the third is the kind of thing that would be straightforward for the company to rebut with a current certificate, and it sits awkwardly beside a 2019 warning letter about product claims.

The Rest of the Range

Beyond the two products above, Koi sells conventional CBD tinctures, gummies, topicals, vapes and pet products, plus delta-8, delta-9, delta-10, HHC, THC-P and THCA lines.

The regulatory exposure here is among the highest we have assessed. From 12 November 2026, the FY2026 agriculture appropriations law caps finished hemp-derived consumer products at 0.4mg of total THC per container and excludes cannabinoids synthesised outside the plant entirely rather than capping them. Delta-8, delta-10, HHC and THC-O are all typically produced by chemical conversion, which places them under the outright exclusion. THCA is caught directly by the switch to counting total THC.

The plain CBD line and the THCV products — THCV being neither intoxicating nor delta-9 — are the parts of the catalogue least disturbed by that.

Who Should Not Use These Products

This review is information, not medical advice, and nothing here promises any outcome or should be used to change a prescribed treatment. Talk to a clinician or pharmacist first.

• Anyone with a history of depression or anxiety should discuss THCV specifically, given the CB1 blockade mechanism and the rimonabant precedent above.
• Anyone pregnant or breastfeeding, or under 21 for the intoxicating lines.
• Anyone considering vaping THC-O — the ketene finding applies to combustion, and we would advise against it outright.
• Anyone taking medication metabolised by the liver — CBD inhibits CYP3A4 and CYP2C19.
• Anyone with liver disease, or subject to workplace drug testing.
• Anyone with reflux, gastritis or oesophageal problems should note that apple cider vinegar is acidic, even at these small amounts.
• Anyone on a GLP-1 should not treat THCV as a substitute for it, and should raise any addition with the prescriber managing their treatment.

How Koi Compares

Across ten hemp brands, Koi has the weakest combination of regulatory history and testing confidence, and it sells the single product we would most actively warn against — THC-O in a vapeable format. If you want CBD, CBDfx and R&R are better documented and cheaper to verify.

Pros and Cons

Who Should Pick It, and Who Should Look Elsewhere

Koi suits you if you specifically want to try THCV, which is genuinely hard to find elsewhere and is the one part of this range with an interesting evidence base. If that is you, buy it for the THCV and ignore the apple cider vinegar entirely — and understand you are buying an experiment, not a treatment.

Look elsewhere if you want plain CBD. CBDfx has two accredited laboratories and independently verified potency; R&R has USDA Organic certification and costs less per milligram. Neither carries an FDA warning letter or a contested extraction claim.

Do not buy the THC-O vapes. That is the clearest recommendation in this review, and it rests on published toxicology rather than a legal argument.

And if you came to this page hoping a gummy would help with appetite: the honest answer is that the ingredient with evidence behind it is under-dosed and the ingredient in the name is essentially absent. If appetite control is what you need, that is a conversation with a clinician, not a purchase.

Limitations of This Review

We have not bought, taken or independently assayed any Koi product. The company’s product page did not render for us, so the THCV + ACV composition is taken from retailer listings rather than Koi’s own page — verify it on the packaging. We verified no pricing at all and have published none.

Specific gaps: the testing concerns — outdated certificates, broad-spectrum products containing only CBD, and solvents detected against CO2 extraction claims — come from independent CBD review coverage rather than our own examination of certificates or a formal audit, and we present them as flags rather than established facts. The 2019 FDA warning letter and dismissed class action are seven years old and we have not established the company’s current compliance posture. We did not locate a BBB profile, and Trustpilot coverage was inconsistent between sources, so we publish no customer-satisfaction score. On the research: the THCV trial is small and we relied on published summaries rather than our own reading of it; the ACV comparison uses an approximate density conversion from 30ml to milligrams; and the rimonabant precedent is context about a different and far more potent drug, not a claim about THCV’s safety. Nothing here is medical advice.

Frequently Asked Questions

Verdict

Koi is not a fly-by-night operation. Eleven years of trading, published certificates and clearly printed milligram doses put it ahead of several brands we have reviewed, and THCV is a genuinely interesting compound that most competitors do not stock at all.

But this is the first product in this series aimed directly at what our readers are trying to do, and it does not survive contact with the arithmetic. 600mg of apple cider vinegar against roughly 30,000mg in the research is about two percent, and the underlying ACV evidence is contested even at full strength. The THCV beside it has a real mechanism and a small trial behind it, but at a dose that matches neither the study nor its CBD pairing — and 4.1kg over 90 days is a long way short of what a prescribed GLP-1 achieves. Nobody should buy this expecting the second thing while paying for the first.

The rating is lower still because of THC-O. The legal position is genuinely contested — the DEA says Schedule I, the Fourth Circuit says hemp — but the toxicology is not part of that argument: burning an acetate ester produces ketene, which is the same mechanism behind the vitamin E acetate implicated in EVALI. A company still selling that in a vapeable format in 2026, three years after the finding was published, has made a choice about what it is willing to sell. Buy the THCV if you are curious. Leave the rest.