PhenQ is a weight loss supplement that advertises “five powerful fat scorchers in one simple, daily formula."
In this article we’ll review every ingredient in PhenQ, as well as its dosage, based on published medical research to provide our determination on whether this supplement is actually likely to be effective for weight loss, or whether it's a waste of money.
Because PhenQ has many ingredients, we will break our ingredient review into two sections: Active Ingredients and Inactive Ingredients.
Active Ingredient Review
We typically include an image of the Supplement Facts label when reviewing a supplement on Illuminate Health, but PhenQ published such a low-resolution Supplement Facts label to their website that we'll have to just list the ingredients; their label is barely legible.
The first two active ingredients in this formulation are the minerals calcium and chromium.
A medical review of chromium supplementation for weight loss, published in the Obesity Reviews journal, analyzed the results of more than 10 individual trials and found chromium to be effective for weight loss. However, the dose used in every single study was higher than the 80 microgram (mcg) dose in PhenQ.
The majority of clinical trials used a chromium dosage over 400 mcg, so we will consider this ingredient to be underdosed in PhenQ's formulation.
We do not recommend that consumers take supplemental calcium without a doctor's approval, because this mineral may increase risk of heart disease in some patients according to a 2018 medical review. Calcium is also easily obtainable from diet.
L-carnitine fumarate is included at a dose of 150 milligrams (mg). A medical review published in the Obesity Reviews journal found that l-carnitine (but not l-carnitine fumarate specifically) was modestly effective for weight loss. This review is cited by PhenQ on their website. Trial participants taking supplemental carnitine lost an average of 2.93 pounds, and trial durations ranged from 30 to 360 days.
However, the lowest dose used in any of the included clinical trials was 2,000 mg per day, or over 13x the amount in PhenQ. We find it to be highly questionable that PhenQ cites a medical study as evidence of efficacy, while that same study includes vastly higher doses than this supplement. We will consider this ingredient underdosed and likely ineffective.
Caffeine is an active ingredient at a dose of 100 mg, which is around the amount in one cup of coffee. We will consider this to be an effective weight loss ingredient based on a medical research review, but the linked study found higher doses of caffeine to be significantly more effective.
Nopal cactus fiber is included at a comically low 20 mg dose. The medical study that PhenQ cites to back this ingredient used a daily dose of 3,000 mg, or 150 times the amount in PhenQ.
This supplement contains a blend called "Capsimax Plus Blend" in reference to one trademarked ingredient called Capsimax. The total dose of the blend, which contains four ingredients, is 50 mg. This equates to an average ingredient dose of 12.5 mg.
Capsimax's own website lists the effective dose as 100 mg, or 8 times higher than the average ingredient dose in this blend.
The final active ingredient in this formulation is a trademarked blend called "a-Lacys Reset" which contains alpha lipioc acid, cystein and magnesium. We cannot identify any medical research proving this ingredient to be effective for weight loss. The two citations PhenQ makes to studies in medical journals in reference to this ingredient test the effects of alpha lipoic acid, but not this specific blend. Both trials also use significantly higher doses than that in PhenQ.
Overall we are underwhelmed by the active ingredients in PhenQ. This supplement may be effective for weight loss because many of its ingredients have proven efficacy for weight loss. However, we only consider one of the active ingredients to be effectively dosed based on medical research.
Questionable Inactive Ingredients
PhenQ contains several questionable filler ingredients that we recommend consumers avoid.
The supplement contains artificial food dye FD&C blue #1 to color the product. There is legitimate medical concern over the toxicity of food dye as an additive, and while the amount used in PhenQ is almost certainly low, we recommend avoiding products with artificial food dye altogether.
PhenQ also contains potassium sorbate which is a preservative. This ingredient is Generally Recognized As Safe (GRAS) by the Food and Drug Administration (FDA), but we typically recommend avoiding preservatives altogether as they provide no nutritional value and research on their long-term safety is still developing.
Questionable Medical Studies
PhenQ claims that their product is “backed by real science” and highlights an graph suggesting that one patented ingredient in their formulation is effective.
The citation for this graph is not medical research published in a legitimate medical journal, but rather references a clinical trial conducted by a for-profit research company called "Principium Beauty Systems Innovations." The full study is not shared or linked to on PhenQ's website.
We do not agree with their conclusion that this ingredient is proven to be effective for weight loss, because as stated in the Active Ingredient review section, we were unable to locate any clinical trials published in legitimate medical journals proving this ingredient to be effective.
We disagree with the practice of supplement manufacturers making health claims based on "clinical trials" conducted by for-profit research institutions, and we recommend that consumers only take into account clinical trials published in legitimate medical journals.
Our Weight Loss Supplement Recommendations
There are several weight loss products that we recommend due to their research backing and lack of side effects.
Dietary fiber is a safe and effective weight loss supplement.
An extensive medical review published in The Journal of Nutrition found that dietary fiber intake directly predicts weight loss when consumed at a high enough dose. Fiber is zero-calorie plant matter that makes you feel full faster, and consume fewer calories overall.
The fiber supplement we recommend is SuperGut Fiber Mix. It contains a clean and effective formulation: a blend of three different types of unflavored dietary fiber and zero additive ingredients. It can be mixed into liquids or foods. Interested consumers can buy SuperGut fiber at this link.
We recommend using two fiber mixes per day, which provides 16 grams (g) of fiber. This is within the effective fiber dosing range associated with the greatest weight loss outcomes in the above-linked study.
Medium-chain triglyceride (MCT) oil is another dietary supplement which has been shown in clinical trials to cause weight loss.
MCT oil is quickly absorbed by the body and increases metabolic rate, which causes fat loss. A meta-study on MCT oil documented weight loss of 1.12 pounds over 10 weeks. This equates to a potential annualized weight loss of 5.84 pounds with MCT oil supplementation.
We recommend Bulletproof MCT Oil as our top MCT oil product, because it has a clean and effective formulation. The only ingredient is MCT oil derived from coconuts, and the product has no questionable additives. Interested consumers can buy Bulletproof MCT Oil at this link.
The effective dose range of MCT oil for weight loss (based on the medical review) is 1.7 g to 10 g per day. Bulletproof's MCT oil provides 14 g in one tablespoon, so around two-thirds of one tablespoon should be a maximally-effective dosage.