Many health‑conscious parents, caregivers, and biohackers are hearing more about C15 (also called C15:0 or pentadecanoic acid) as a promising emerging fatty acid. But how much do we really know? And how do you increase C15 naturally or via diet and supplementation. Especially for children or families avoiding dairy or animal fats? In this guide, I’ll explain:
What C15 is and why it matters
Natural and supplemental sources
Practical dietary strategies.
Vegan/vegetarian solutions
Safety, limitations, and next steps
What Is C15 (Pentadecanoic Acid) — And Why It’s Gaining Attention?
The basics: C15 / C15:0
C15:0, or pentadecanoic acid, is an odd-chain saturated fatty acid (i.e. 15 carbons, zero double bonds).
It’s called “odd-chain” because most saturated fats we commonly talk about (like palmitic acid, stearic acid) are even-chain.
Unlike many other saturated fats, C15:0 is being studied for potential protective, metabolic, anti-inflammatory, and longevity-related roles.
Why people are excited
Some emerging observations suggest:
Higher circulating levels of C15:0 correlate with lower risk of diabetes, cardiovascular disease, and mortality.
Animal and in vitro studies propose anti-inflammatory effects, support for mitochondrial function, and beneficial effects on metabolic markers.
Some early human research and supplement trials are underway, exploring whether boosting C15 has therapeutic effects.
However, caution is warranted:
Nutrition authorities and mainstream lipid experts still consider the evidence preliminary, not conclusive.
As of now, C15 is not universally recognised as an “essential fatty acid.”
We don’t yet have well-established target blood levels, recommended daily intake, or long-term safety data.
So, while boosting C15 is an intriguing strategy, it should be approached with balance and awareness.
Natural (Food) Sources: How to Get C15 Naturally
If you prefer to emphasise “food first” strategies, here are the natural sources and limitations. In many cases the amount in foods is quite low.
Animal and dairy sources (the richest sources)
These tend to be the most reliable sources of C15:0:
Full-fat dairy (butter, cream, whole milk, cheese) — C15 may make up ~0.5-1% of total fat.
Beef, lamb, ruminant fat — especially from grass-fed animals.
Fatty fish — though amounts are modest compared to dairy or ruminant fat.
Tips for maximising from animal/dairy sources:
Prefer grass-fed, pasture-raised animals — their fat tends to have a healthier lipid profile and may hold higher levels of beneficial fatty acids.
Opt for full-fat over low-fat dairy when dairy is tolerated.
Use butter or ghee (especially from grass-fed cows) in cooking.
Include moderate amounts of fatty cuts from beef, lamb, or ruminants in your diet.
Rotate in oily fish (e.g. salmon, sardines).
Plant / vegan / trace sources of C15
Pure plant sources of C15 are very limited and usually exist only in trace amounts:
Seaweed and some algae may contain trace amounts.
Some exotic plants, such as Durio graveolens, contain small proportions of C15.
A few vegan foods like chia seeds and mushrooms may contain minor pentadecanoic acid content.
Because the quantities are so low, you can’t reliably meet meaningful C15 intake from plants alone. For strict vegans or dairy-avoidant individuals, supplementation becomes more relevant. The best vegan C15 supplement is Fatty 15.
For more about Fatty15, see Fatty15 Foods And Supplements.
How to Increase C15: Strategies & Tips
| Strategy | What to Do | Notes / Considerations |
|---|---|---|
| Add grass-fed dairy and animal fats | Use grass-fed butter, ghee, full-fat dairy; include grass-fed beef or lamb, fatty fish | Balance with overall saturated fat intake |
| Improve absorption | Pair with good fat digestion (e.g. bile support, enzymes) | Ensures C15 you eat is absorbed |
| Support gut microbiome pathways | Feed fibres, resistant starch, inulin | May contribute to odd-chain FA levels |
| Supplement with pure C15 (Fatty15) | Use vegan, free fatty acid form of C15:0 | Ideal for vegans and precise dosing |
| Monitor biomarkers | Track lipids, liver enzymes, health outcomes | Tailor to individual responses |
Supplementation
For those who avoid animal sources, Fatty15 is a clean, vegan-friendly way to supplement. This is recommended as adequate amounts of C15 fatty acid is difficult to obtain via the diet.
Fatty15 offers a pure, free fatty acid form of C15.
It allows for precise dosing and avoids the saturated fat load from animal foods.
Especially valuable for vegans, children with sensitivities, or those needing convenience.
Link for more info: Fatty15, which includes a 10% discount.
Meal Ideas
Omnivore sample day:
Breakfast: Grass-fed butter eggs + avocado + sardines
Lunch: Grass-fed burger with cheese and veggies
Dinner: Roasted lamb with ghee-sauteed kale
Vegan sample day (with Fatty15):
Breakfast: Oatmeal + chia + almond milk + FA15
Lunch: Hummus wrap + broccoli
Dinner: Stir fry + wild rice + FA15
Safety, Risks & What We Don’t Know
While research looks promising, be cautious:
Dosage: Optimal dosing still unclear
Long-term: No large human trials yet
Children: Consult pediatric experts before introducing
Interactions: Unknown effects with medications or other supplements
Because C15 supplementation is relatively new, it’s important to be cautious.
What we know:
Early trials and animal studies have not reported major safety signals. Genetic Lifehacks.
Observational correlations show higher C15 levels are associated with better health outcomes. Genetic Lifehacks.
What we don’t yet know:
Causation vs correlation: we don’t yet have strong evidence that raising C15 causes improvements in health outcomes.
Optimal dosing: targets for blood levels, how much intake is ideal, and spacing are still under research.
Long-term effects: multi-year human trials are lacking.
Interactions: how it interacts with lipid metabolism, cholesterol, medications, or pre-existing conditions.
Populations: how supplementation affects children, pregnant women, or those with metabolic disorders.
Given that, here are some safety tips:
Start with low to moderate doses, then monitor effects.
Work with medical or nutritional professionals, especially for children or individuals with lipid or cardiovascular risk.
Monitor lipid panel, liver enzymes, inflammation markers, and overall health outcomes.
Avoid excessive saturated fat ingestion just to chase C15 — remember that balance matters.
Stay within reason: don’t assume “more is better” until more data exists.
Scientific Insights & Mechanisms
Emerging research suggests that C15:0 may exert its benefits by:
Supporting mitochondrial membrane stability
Reducing oxidative stress and inflammation
Enhancing cellular metabolism
Modulating peroxisome proliferator activated receptors (PPARs) — which regulate gene expression related to fat metabolism and inflammation
These mechanisms are still under investigation but represent exciting possibilities for metabolic and neuroinflammatory conditions, including those relevant to autism.
How C15 May Support Children with Autism
While clinical trials in children with autism are lacking, some theoretical benefits of increasing C15 intake may include:
Supporting cell membrane integrity
Enhancing mitochondrial function, often implicated in autism spectrum disorders
Reducing chronic inflammation
Providing a cleaner alternative to fish oil for sensitive individuals
Parents interested in this route should consult with integrative paediatricians or registered dietitians experienced in autism nutrition.
Summary & Next Steps
C15 (pentadecanoic acid) is an emerging odd‑chain saturated fatty acid that shows promise in preliminary research for metabolic, anti-inflammatory, and longevity support.
Natural food sources (especially grass‑fed animal fats and full-fat dairy) offer the most reliable intake, but amounts are low and require balance with other fats.
Plant sources exist only in trace amounts and are not sufficient alone for boosting C15 meaningfully.
Supplementing with pure C15 (e.g. Fatty15) is a practical option for vegans, low-dairy diets, or precision dosing.
Use a balanced, cautious approach, monitor biomarkers, and consult professionals.
Because this is a frontier area, stay tuned for new research, clinical trials, and guidelines.
Final Thoughts
C15 may be a missing piece in fatty acid nutrition, especially for mitochondrial, metabolic, and inflammatory health.
For most, adding grass-fed fats and/or taking Fatty15 is the best way to increase C15 intake.
Vegans can rely on Fatty15 without compromising their lifestyle.
Research is still growing, so track your personal health outcomes and stay updated.
Frequently Asked Questions (FAQ)
Is C15 truly “essential”?
Not officially — mainstream authorities have not yet recognised it as essential, though some researchers argue it should be reclassified.
Can our bodies make C15 from other fats?
Endogenous synthesis is minimal; most C15 comes from diet or possibly microbial fermentation in the gut.
How much C15 should one aim for?
There is no RDI, but emerging suggestions point toward 100–300 mg/day based on observational and experimental data.
Will increasing C15 raise cholesterol?
So far, research suggests C15:0 may support healthier lipid profiles, but individual monitoring is essential.
Can I give C15 to my child?
Consult your child’s healthcare provider. Some parents use Fatty15, but safety data in paediatric populations is limited.
