Pentadecanoic Acid Research: A Timeline of Key Studies (2015–2026)

Some of the most important scientific discoveries start in the most unexpected places. This one started with dolphins.

While working to improve the health and welfare of aging Navy dolphins, veterinary epidemiologist Dr. Stephanie Venn-Watson noticed something worth noting. The healthiest, longest-living dolphins in the program had higher levels of a particular odd-chain fatty acid in their blood: C15:0, also known as pentadecanoic acid.

It was not a nutrient anyone had paid much attention to before. And, as a saturated fatty acid, this nutrient had spent decades being wrongly lumped in with the “bad” fats that dietary guidelines had warned us away from since the 1970s.

Dr. Venn-Watson’s initial discovery of C15:0 as a foundational nutrient was made in 2015. What followed has been one of the more remarkable runs of accumulating scientific evidence in recent nutritional science. To date, over 150 peer-reviewed publications describe the health benefits of C15:0, and the story is still being written.

Here is a look at where the research has been, where it is now, and where it is headed.

A Quick Primer: What Is C15:0?

C15:0 is an odd-chain saturated fatty acid, meaning it has 15 carbon atoms. Odd-chain because of that number. Saturated because it has no double bonds, which also makes it chemically stable in a way that many other fats are not.

Science now supports that not all saturated fats behave the same way. Odd-chain saturated fatty acids have a distinct and beneficial health profile, and there are growing calls from the scientific community to update dietary guidelines accordingly.

C15:0 is emerging as the third essential fatty acid ever discovered and the first in more than 90 years. “Essential” means our bodies cannot make adequate amounts on their own, and we must get it through diet or supplementation to maintain baseline physiological health.

2020: The Foundational Paper That Started It All

Dr. Venn-Watson’s team at the Navy discovered C15:0 as a beneficial saturated fatty acid in 2015 and over the next 5 years, continued to study its long-term health benefits. They published a summary of their findings supporting C15:0 as having broad health benefits in a 2020 publication in Nature’s Scientific Reports.

Dr. Venn-Watson and her team demonstrated that C15:0 was not just associated with better health outcomes. It was causing them. The paper showed that C15:0 directly strengthens cell membranes against age-related breakdown, improving cellular stability by 80%.

It also demonstrated that C15:0 activates PPARα and PPARδ receptors, which regulate metabolism, immunity, mood, sleep, and appetite. Additionally, C15:0 activates AMPK, the cellular energy sensor that helps regulate glucose uptake and whole-body homeostasis, and inhibits mTOR and JAK-STAT pathways, both of which are established targets in longevity science.*

The paper also showed that C15:0 directly enables mitochondrial repair. As our mitochondria age, they lose function, producing more damaging reactive oxygen species (ROS) and less usable energy. C15:0 reversed this dysfunction.

The result is improved cellular energy output and a 45% reduction in damaging reactive oxygen species.*

2021 to 2022: Establishing Essentiality and Breadth of Activity

In the years following the foundational discovery and paper, independent research teams began replicating and expanding on the initial findings. Over 20 peer-reviewed publications on C15:0 appeared during 2021 alone, from institutions including Harvard and Johns Hopkins, further supporting C15:0’s broad health benefits.

These benefits included further confirmation of C15:0’s role in supporting liver, cardiometabolic, and cardiovascular health, as well as longevity in humans, and demonstrated C15:0’s anticancer, insulin-sensitizing, antibacterial, and antifungal activities. The essentiality hypothesis gained substantial traction. A second independent team proposed C15:0 as an essential fatty acid.

Further, a review paper showed that low C15:0 levels, defined as below 0.2% of total fatty acids, could result in a newly proposed nutritional deficiency syndrome called Cellular Fragility Syndrome, which may be affecting as many as 1 in 3 people globally.

This syndrome involves a newly discovered form of cell death called ferroptosis, where fragile cell membranes undergo lipid peroxidation, leading to iron overload, mitochondrial dysfunction, and accelerated cellular aging.

A key 2022 study tested C15:0 across 12 primary human cell disease systems using the BioMAP Diversity PLUS panel, an independent, industry-standard pharmacological assay system that measures activity across 148 clinically relevant biomarkers. C15:0 showed 36 dose-dependent, clinically relevant activities across 10 of 12 cell systems. It was safe at all concentrations tested.

For context, the pure omega-3 fatty acid EPA exhibited seven activities in the same panel and showed toxicity in some cell systems at higher doses. In the end, C15:0 was broader, safer, and more active.

2023: C15:0 Goes Head-to-Head With Leading Longevity Compounds

The 2023 study published in the journal Nutrients took the comparison further, pitting C15:0 against three of the most-studied longevity-enhancing compounds: rapamycin, metformin, and acarbose.

At their optimal doses, C15:0 and rapamycin shared 24 significant cell-based activities across 10 of 12 cell systems, including healthy inflammatory response, antifibrotic, and anticancer activities. C15:0 had 36 annotated activities total. Rapamycin had 32. Metformin had 17. Acarbose had 5.

Rapamycin is a prescription drug discovered in bacteria on Easter Island. Metformin has been used as a medicine for nearly four centuries and is the most common first-line treatment for type 2 diabetes globally. Acarbose is a prescription diabetes drug. C15:0 is a fatty acid found in dairy fat, now available as a single-ingredient supplement. In this head-to-head comparison, C15:0 outperformed rapamycin, metformin and acarbose.

The same study also confirmed C15:0 as addressing 6 of the 12 recognized hallmarks of aging, including mitochondrial dysfunction, cellular senescence, impaired cellular signaling, and inflammaging, the chronic low-level inflammatory state that accelerates many age-related diseases.

In addition to this paper, independent teams published peer-reviewed studies on C15:0’s role in suppressing advanced fatty liver disease in preclinical models and its greater efficacy than C17:0 in models of metabolic syndrome and type 2 diabetes.

Further, among all circulating fatty acids evaluated in an extensive human population cohort study, only C15:0 was associated with a lower risk of colorectal cancer. In a separate study, higher circulating C15:0 during pregnancy in women was strongly associated with healthier fetal body weight and size.

2024: Population-Level Evidence and Clinical Trials

In addition to large-scale epidemiological research and preclinical studies, clinical trials continued to build the case for C15:0’s health benefits for humans.

A prospective cohort study following over 4,000 people for 16 years found that individuals with C15:0 levels of 0.40% to 0.55% of total fatty acids had the lowest risk of developing heart disease.

People living in the longevity Blue Zone of Sardinia, Italy, a region noted for the highest percentage of men worldwide who live to at least 100, had C15:0 levels of 0.64%, roughly three times those of the general population. Their diet, rich in cheeses from locally grazing goats and sheep, is notably high in C15:0.

The 2024 TANGO randomized controlled trial brought C15:0 into direct human clinical testing. In a double-blind, parallel-group trial, participants following a Mediterranean-style diet with C15:0 supplementation achieved greater reductions in body weight, liver fat, cholesterol, and triglycerides than those following the diet alone. The C15:0 group also showed further reductions in LDL cholesterol and beneficial shifts in the gut microbiome.

A separate 2024 clinical trial in young adults confirmed that supplementation with 200 mg of C15:0 per day successfully raises circulating C15:0 levels. When these levels were raised above a critical threshold, they supported liver and red blood cell health.

On the emerging essential fatty acid front, one independent group demonstrated that C15:0 alone could restore normal neuronal development in nutrient-deprived C. elegans, while another team provided a review of human data supporting C15:0 as an emerging essential fatty acid.

2025 and Beyond: Brain Health and Emerging Frontiers

A 2025 study published in the International Journal of Molecular Sciences added a compelling new dimension to the C15:0 story.

Researchers examining archived brain tissue from aging Navy dolphins, which naturally develop amyloid-beta plaques and neuroinflammation similar to those in humans with Alzheimer’s disease, found that C15:0 demonstrated dose-dependent inhibition of two key enzymes involved in cognitive health: FAAH, with up to 89% inhibition, and MAO-B, with up to 70% inhibition.*

Both enzymes are linked to amyloid-beta processing, neuroinflammation, and dopamine regulation, suggesting that C15:0 may support long-term cognitive health through mechanisms that extend beyond metabolism.

2025 and 2026 delivered a slew of independent, peer-reviewed studies on C15:0. This included C15:0’s role as an mTOR inhibitor and proposed role in slowing age-related infertility, along with a separate paper demonstrating C15:0’s direct placental support during pregnancy. On the anticancer front, C15:0 had anticancer effects on bladder cancer and specifically targeted certain B-cell lymphomas.

Relevant to C15:0’s emerging role as an essential fatty acid, multiple benefits — from improving red blood cell and liver health to lowering oxidative stress, inflammation, and ferroptosis — were demonstrated in a model of C15:0 deficiency syndrome. Further, another team put C15:0 to the test using a hallmark nutritional deficiency model, which showed that C15:0 met the criteria of an essential fatty acid just as well as linoleic acid, an established essential fatty acid.

Large prospective cohort meta-analyses including large human populations tracked globally over long periods of time continued to show that people with higher C15:0 levels have a lower risk of developing type 2 diabetes and cardiovascular disease. Another study repeated associations between higher circulating C15:0 and lower risks of hypertension.Why C15:0?

C15:0 is primarily found in trace amounts in whole-fat dairy products. Simply increasing butter or whole-fat milk consumption, however, may not be the most practical solution for most adults.

Whole-fat dairy comes with a significant load of calories, sugars (lactose), and even-chain saturated fats, which are still associated with poorer health outcomes. The good C15:0 comes along with a lot of things most people aren’t looking for.

Reputable C15:0 supplements contain bioavailable C15:0 powder already in free fatty acid form, ready for absorption without the extra steps required when C15:0 is bound to triglycerides in food.