What is Fatty15
If you have not seen the marketing on Fatty15, it is very expensive dietary supplement claiming to be the first essential fatty acid discovered in over 90 years that is useful in improving health span and cellular longevity. These are bold statements that simply are FALSE based upon current scientific evidence.
Fatty15 contains the saturated fat pentadecanoic acid (C15:0). There is NO credible scientific basis for the claim that the fat pentadecanoic acid (C15:0) is an essential fatty acid. And no recognized scientific organization or group of experts supports this claim or the claims of health benefits being touted.
Most fatty acids in the body have an even number of carbon molecules in their chain. With 15 carbons and no unsaturated bonds, pentadecanoic acid (C15:0) is a saturated, odd-chain fatty acid. The human body produces C15:0. It is also found in dairy fat and produced by bacteria in the human gut microbiome.
C15:0 as a Dietary Supplement
Though Fatty15 claims health benefits as a dietary supplement, these claims have not been proven. In fact, the human clinical evidence shows only small, clinically insignificant effects and no real benefit.
The promotion of Fatty15 includes cited research based almost exclusively on cell and animal conducted by the co-founder or entirely funded by the company.1,2 And none of the health claims have been confirmed sufficiently in human clinical trials or by independent research.
Keep in mind that it is quite common that animal and cell research shows promise for a natural compound or drug, only to find out that in actual human clinical studies the compound does pan out. Based upon current human data, that appears to be the likely outcome with C15:0 supplementation.
A Closer Look at the Science
The Fatty15 story began with a finding that higher pentadecanoic acid levels were associated with healthier, older dolphins. An association is a finding that two things are linked but may not reflect a direct effect. For example, a paper cut may draw blood, but the blood did not cause the cut.
For the association to be shown to have a direct effect, Fatty15 would have to produce the claimed benefits of improved metabolic, heart, liver, immune, and gut health in human clinical studies. The association of higher C15:0 in healthy dolphins may turn out to not have any relevance as a dietary supplement in humans. It may be simply an association without a direct effect.
Clinical Studies with C15:0
The published controlled human clinical trials to date show very little benefit with Fatty15 even at dosages of 300 mg per day (at a real-world cost of ~$150 per month). Let me highlight the two studies available on PubMed as proof.
In one study, 30 overweight or obese young adults were randomly assigned to take either 200 mg of C15:0 or a placebo every day for 12 weeks. Overall, the results showed no effect. However, it is important to point out that any health benefit blood levels of pentadecanoic acid may require that it reach a threshold of 5 μg/mL in the blood. Only about half of the subjects reached that level. In those that did, there was some evidence of slightly improved liver function and hemoglobin levels.3
Though the overall results were not significant, it may indicate that higher dosages (e.g., >300 mg a day) are likely needed for most people to see any benefit, even if that benefit is likely to be only described as “small.” At this dosage and at a cost of $150 per month in real life, better results at a lower price point are better obtained through diet, lifestyle, or with the help of more effective dietary supplements.
Another study proves this point.4 In this study, 88 Chinese women living in Singapore with non-alcoholic fatty liver disease (NAFLD), a condition linked to obesity and poor metabolic health, were randomly assigned to one of three groups for 12 weeks:
- Mediterranean-style Asian diet + 300 mg of pentadecanoic acid (31 women)
- Mediterranean-style Asian diet without supplement (28 women)
- Control group (kept usual diet, no supplement, 29 women)
The results showed that 90% of the benefits were attributed to dietary changes with C15:0 only producing a mild additive effect. Results showed diet alone produced major improvements in weight loss, liver fat, and blood levels of cholesterol, triglycerides, and liver enzymes. C:15 is most likely to produce no significant effect on these markers on its own based upon this study.
OK, let me shed more light on the significance of the small effect of C15:0. Clinically it means NOTHING. And it pales in comparison with several highly effective dietary supplements like black seed oil (.e.g., Thymoquin®, berberine,fish oils, and many others that are available at clinically effective dosages at only a fraction of the monthly cost of Fatty15.
Comparing Fatty15 to Other Natural Products
To highlight the advantages of other product over Fatty15, let’s take a look at ThymoQuin®, the “gold standard” in black seed oil (BSO). Human clinical trials with BSO supplementation in overweight women between 25 to 50 years old has been shown to reduce oxidative stress, inflammation, and insulin resistance. This translates to producing improved metabolic health, liver function, blood sugar control, and weight loss.5
In one study, C-reactive protein (CRP), a well-known risk factor of cardiovascular disease and metabolic health, was reduced by 54.5% in the BSO group versus 21.4% in the placebo group.6 And in another double-blind study, ThymoQuin®, the gold standard in BSO, produced immune-enhancing effects, improved overall well-being, and lowered salivary cortisol levels by a whopping 44%.7
Here is a table comparing the clinical benefits of Fatty15 to ThymoQuin®, berberine, and fish oils from published human randomized, double-blind, placebo-controlled trials.5-10
Comparative Effects of Fatty15 to Other Natural Metabolic Aids
| Ingredient | NAFLD | Insulin sensitivity | Cholesterol & Triglycerides | C-reactive protein (CRP) | Cortisol |
| Fatty15 (C15:0) – 300 mg daily | Minimal effect as C15:0 reduced liver fat only 3%, more than diet alone | No effect. | Added LDL-C reduction with C15:0; TG and TC fell with diet. | No effect. | No effect. |
| ThymoQuin®, Black seed oil (Nigella sativa) – 500 mg twice daily | Significantly improves fatty liver congestion and lowers liver enzymes (ALT/AST) | Improved FPG, HbA1c, and insulin sensitivity (HOMA-IR) | Significant actions in ↓ TG, LDL-C, TC; and ↑ HDL-C. | Significant CRP reductions (e.g., 54%) | Lowers cortisol (-44%) and improves stress/sleep. |
| Berberine – 500 mg two to three times daily before meals | Improves liver enzymes, insulin sensitivity (HOMA-IR), and blood lipids | Significant improvements in insulin sensitivity (HOMA-IR) and blood sugar control. | Significant actions in ↓ TG, LDL-C, TC | Lowers CRP in type 2 diabetes and metabolic syndrome | No consistent human evidence. |
| Fish oils – ~1,200 mg EPA+DHA daily | ↓ liver fat, ↓ ALT, ↓ TG, ↑ HDL-C. | Modest HOMA-IR improvement in subjects with insulin resistance | Consistently ↓ TG; and ↑ HDL-C; LDL-C variable. | Modest CRP reduction. | Lowers cortisol by ~10-15% |
Final Comments
Why would anyone spend $150 a month on a product that produces no real effect? The answer is obviously marketing. Hence my question is Fatty15 is “fool’s gold?”
My passion is helping people get results with natural approaches to health. With that goal in mind, at this time, I recommend investing in other dietary supplements over Fatty15 if you are seeking the benefits this expensive supplement is claiming to produce.
References:
- Venn-Watson S, Lumpkin R, Dennis EA. Efficacy of dietary odd-chain saturated fatty acid pentadecanoic acid parallels broad associated health benefits in humans: could it be essential? Sci Rep. 2020 May 18;10(1):8161.
- Venn-Watson S. The Cellular Stability Hypothesis: Evidence of Ferroptosis and Accelerated Aging-Associated Diseases as Newly Identified Nutritional Pentadecanoic Acid (C15:0) Deficiency Syndrome. Metabolites. 2024 Jun 23;14(7):355.
- Robinson MK, Lee E, Ugalde-Nicalo PA, et al. Pentadecanoic Acid Supplementation in Young Adults with Overweight and Obesity: A Randomized Controlled Trial. J Nutr. 2024 Sep;154(9):2763-2771.
- X, Wanjaya ER, Elejalde U, Goh CC, et al.; TANGO Study Group. Effect of an Asian-adapted Mediterranean diet and pentadecanoic acid on fatty liver disease: the TANGO randomized controlled trial. Am J Clin Nutr. 2024 Mar;119(3):788-799.
- Arshad MT, Maqsood S, Ikram A, Abdullahi MA. Functional, Nutraceutical, and Pharmacological Properties of Black Seed. Food Sci Nutr. 2025 Aug 19;13(8):e70725.
- Mahdavi R, Namazi N, Alizadeh M, Farajnia S. Nigella sativa oil with a calorie-restricted diet can improve biomarkers of systemic inflammation in obese women: A randomized double-blind, placebo-controlled clinical trial. J Clin Lipidol. 2016 Sep-Oct;10(5):1203-11.
- Talbott SM, Talbott JA. Effect of ThymoQuin Black Cumin Seed Oil as a Natural Immune Modulator of Upper-Respiratory Tract Complaints and Psychological Mood State. Food Sci Nutr Res. 2022; 5(1): 1-6.
- Rashidmayvan M, Mohammadshahi M, Seyedian SS, Haghighizadeh MH. The effect of Nigella sativaoil on serum levels of inflammatory markers, liver enzymes, lipid profile, insulin and fasting blood sugar in patients with non-alcoholic fatty liver. J Diabetes Metab Disord. 2019 Sep 11;18(2):453-459.
- Liu D, Zhao H, Zhang Y, Hu J, Xu H. Efficacy and safety of berberine on the components of metabolic syndrome: a systematic review and meta-analysis of randomized placebo-controlled trials. Front Pharmacol. 2025 Jul 16;16:1572197.
- Kar R, Panchali T, Das P, Dutta A, Phoujdar M, Pradhan S. Overview of the therapeutic efficacy of marine fish oil in managing obesity and associated metabolic disorders. Physiol Rep. 2024 Oct;12(19):e70019.
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