Seraphina Therapeutics · C15:0 Supplement
Fatty15. Strengthen your cells. Slow your aging.
Pure, patented C15:0 — the essential fatty acid your body needs but can't make.
“I have much more energy, no crashing at 3 o'clock, improved brain functioning, and hair growth. I never experienced a change from a supplement like this before.”
— Susan, verified customer
36+
Cellular benefits
- Pure & Patented C15:0
- Vegan Friendly
- Award-Winning
- Third Party Tested
- One Small Pill Per Day
Fatty15 | Fatty15
Fatty15 is a dietary supplement containing pure pentadecanoic acid (C15:0), an essential fatty acid that supports various aspects of health, including metabolism, immunity, gut health, and heart health. This vegan-friendly supplement is free from fillers and additives.
Key Features:
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Single Ingredient Formula: Each capsule provides 100 mg of pure C15:0, without any fillers or additives.
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Vegan-Friendly: The capsules are made from vegetable cellulose, making them suitable for those following a vegan or vegetarian diet.
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Supports Overall Health: C15:0 has been linked to benefits such as enhanced cellular health, improved metabolism, and increased longevity.
Ingredients:
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Active Ingredient: Pure pentadecanoic acid (C15:0) – 100 mg per capsule.
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Other Ingredients: Vegetable cellulose (capsule).
Fatty15 offers a convenient way to incorporate C15:0 into your daily routine, supporting various aspects of health with a simple, vegan-friendly supplement.
Whole Body Health
One nutrient, five vital systems.
C15:0 supports clinically relevant improvements across your body's most critical systems — demonstrated in cell-based, in vivo, and clinical studies.*
Brain
Supports healthy dopamine and endocannabinoid levels for improved cognitive function, deeper sleep, and calmer mood.*
Metabolism
Activates AMPK and AKT pathways to promote healthy glucose control and energy. Linked to lower type 2 diabetes risk.*
Red Blood Cells
Strengthens cell membranes against premature breakdown and oxidative stress. Raises healthy haemoglobin levels within 12 weeks.*
Liver
Activates PPARɑ/δ to lower liver inflammation and fibrosis. Clinical trials showed reduced ALT and AST within 12 weeks.*
Immunity
Calms 18+ proinflammatory cytokines including IL-6, TNFɑ, and MCP-1 across multiple human cell-based systems.*
The Science
3× more cellular benefits than omega-3.
In head-to-head testing across 12 primary human cell-based disease systems, pure C15:0 demonstrated 36 clinically relevant cellular benefits — compared to just 7–10 for omega-3 (EPA).
Unlike omega-3s, C15:0 is a stable saturated fatty acid that strengthens cell membranes rather than making them more susceptible to oxidation. No fishy smell, no taste, no burps — just one small daily capsule.
Both fatty acids support immunity — but C15:0 also offers benefits omega-3 doesn't. They complement each other.
How Fatty15 Works
Repairs cells where they break down with age.
We age because our cells do. Fatty15 targets three core areas of cellular decline.
Strengthens
Cell membranes
80%
C15:0 integrates into cell membranes and makes them 80% more stable, protecting against age-driving lipid peroxidation and ferroptosis — the root cause of cellular fragility.*
Restores
Cellular energy
350%
By repairing mitochondrial function, C15:0 revitalises cellular energy by up to 350% — helping your cells maintain the power they need to function properly as you age.*
Repairs
Cellular signalling
18+
C15:0 activates PPARɑ/δ and inhibits JAK-STAT, calming 18+ proinflammatory cytokines. It also supports healthy dopamine and endocannabinoid levels that naturally decline with age.*
Know Your Levels
1 in 3 people are C15:0 deficient.
As whole-fat dairy consumption has declined, population-wide C15:0 levels have dropped — leaving cells fragile and accelerating aging. The good news: this is measurable and reversible with fatty15.*
Your doctor can order a fatty acid panel that includes C15:0. Fatty15 offers an at-home C15:0 test through Genova Diagnostics, allowing you to track your levels and personalise your dosing.
Every 100mg of fatty15 raises circulating C15:0 by approximately 0.10% (10 µM). This allows personalised dosing to reach your target range.
Optimal
C15:0 > 0.3% to 0.6%
Slower aging. Associated with the longest-lived populations in the Sardinian Blue Longevity Zone. Linked to lower risk of cardiovascular disease, hypertension, and type 2 diabetes.
Average
C15:0 > 0.2% to 0.3%
Normal aging. Cell-based activities support long-term metabolic, liver, cardiovascular, and immune health.
Deficient
C15:0 ≤ 0.2%
Accelerated aging. Increased cellular fragility and higher risk of poorer long-term metabolic and cardiovascular outcomes.
Also Available
The Longevity Nutrient.
The best-selling book by Dr. Steph Venn-Watson, fatty15's co-founder and C15:0 researcher.
Discover the fascinating story behind the discovery of C15:0 — from Navy dolphins to the science of healthy aging. A compelling read for anyone interested in the future of essential fatty acids and what it means for our long-term health.
Real Results
Science-backed. Customer loved.
7,500+
Verified reviews
100k+
Active subscribers
Judy P.
Verified Customer
“I'm stunned by the positive impact fatty15 has had on my health. Skin looks better, I feel stronger, fitter, and my hair seems to be growing in darker. I'm in my mid 60s!”
Dion B.
Verified Customer
“Alongside my daily routine, this supplement has given my system a huge boost. My energy is better and immunity feels stronger. Highly recommend for anyone over 50 seeking natural vitality.”
William B.
Verified Customer
“I have noticed a difference in energy with lower stress levels and a sharper mental acuity. Subtle but real improvements.”
Maribel D.
Verified Customer
“What I struggled with was a lack of energy due to health issues. Now I can say that I feel stronger and less tired. This supplement made a real difference.”
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Answers
Frequently asked questions.
What is C15:0 and why is it considered essential?
C15:0 (pentadecanoic acid) is a healthy odd-chain saturated fatty acid — the first essential fatty acid to be discovered since omega-3 and omega-6, over 90 years ago. It's considered "essential" because our bodies need it to function properly but can't produce enough of it on their own. Over 100 peer-reviewed studies have demonstrated C15:0's broad health benefits, with 36+ clinically relevant cellular activities supporting metabolic, heart, liver, cognitive, red blood cell, and immune health.*Can't I get enough C15:0 from food?
The primary dietary source of C15:0 is whole fat dairy. However, as more people reduce or avoid dairy, population-wide C15:0 levels have been declining. While trace amounts exist in some foods, these also contain much higher levels of pro-inflammatory saturated fats and have C15:0 in a less bioavailable form. Fatty15 delivers pure, bioavailable C15:0 in a concentrated and patented form.*How does fatty15 compare to omega-3?
C15:0 and omega-3 are complementary but different. C15:0 is a stable saturated fat that strengthens cell membranes, while omega-3s are less stable polyunsaturated fats that make membranes more flexible but also more susceptible to oxidation. In head-to-head testing, C15:0 showed 3× more cellular benefits than omega-3 (EPA) across human cell-based disease systems. Both can and should be part of a health routine.*When will I notice benefits?
After 2 weeks, more than half of customers report feeling benefits including deeper sleep, calmer mood, and less snacking. After 4–6 months, 70% report more visible improvements including healthier skin and hair, as well as improved blood markers related to metabolic, immune, heart, or liver health. Clinical trials show measurable changes in haemoglobin, liver enzymes, and cholesterol within 12 weeks.*How should I take fatty15?
Take 1 capsule daily, with or without food. Fatty15 is a tiny, easy-to-swallow capsule with no smell and no taste. Consistency is key — daily use supports steady C15:0 levels in your blood, which is where the long-term health benefits come from.*Can I test my C15:0 levels?
Yes. Your doctor can order a fatty acid panel that includes C15:0. Additionally, fatty15 has partnered with Genova Diagnostics to offer an at-home C15:0 bloodspot test. This lets you measure your levels, identify deficiencies, and personalise your dosing to reach optimal concentrations for long-term health.*