Can You Get C15 from Plants? Understanding Plant-Based Sources

December 26, 2025 •

3 min read

Recent scientific discoveries have sparked interest in the odd-chain saturated fatty acid C15:0, with studies linking higher levels to better health outcomes. However, the primary dietary sources are traditionally animal-based, leading many on plant-based diets to wonder about their options.

Quick Summary

This guide explores the reality of obtaining pentadecanoic acid, or C15, from plant sources. It clarifies that while C15 is present in trace amounts in some plants, it is not bioavailable in significant quantities. The article details how vegans can acquire C15 through endogenous synthesis or supplements derived from plant-based fatty acids, highlighting crucial nutritional considerations.

Key Points

Trace Amounts in Plants: While some plants contain C15, the quantities are too small to be a meaningful dietary source.
Primary Sources are Animal-Based: The main natural sources of C15 (pentadecanoic acid) are whole-fat dairy products and ruminant meat.
Body Can Synthesize C15: The human body can produce C15 internally from propionic acid, a short-chain fatty acid made by gut bacteria.
Supplements are Vegan-Friendly: Vegan C15 supplements are made from plant-based fatty acids in a lab, providing a pure and efficient way to increase levels.
Supplementation vs. Diet: A vegan supplement offers a concentrated dose of bioavailable C15 without the associated even-chain saturated fats and calories found in dairy.
Fiber Supports Synthesis: A high-fiber diet can indirectly boost C15 levels by promoting the growth of gut bacteria that produce propionic acid.

Is C15 Found in Plant-Based Foods?

While the body can produce some C15 (pentadecanoic acid) endogenously, the amount you get from plant-based foods is generally negligible. C15 is a saturated fatty acid primarily found in whole-fat dairy products and certain ruminant meats. Although trace amounts have been detected in some plants, like chia seeds, peanuts, and specific Acacias, they are not a reliable source for meeting optimal C15 levels.

For those on a vegan diet, this presents a significant nutritional challenge. Plant-based milk alternatives, for example, contain no C15:0. To achieve the levels associated with positive health outcomes, consuming whole plant foods would be impractical due to the extremely low concentration of C15 and the high volume of food required. This has led to the development of vegan-friendly C15 supplements designed to provide a targeted dose without animal products.

The Role of Endogenous Synthesis in C15 Levels

Dietary intake is not the only way the body acquires C15. The human body can also produce C15 endogenously through metabolic processes.

Fiber Fermentation: The gut microbiome ferments dietary fiber, producing short-chain fatty acids like propionic acid.
Liver Conversion: This propionic acid is then converted into C15:0 by the liver.

Interestingly, some research has shown that the blood levels of odd-chain fatty acids like C15 are comparable in vegans, vegetarians, and omnivores, suggesting that endogenous synthesis plays a crucial role regardless of diet. This implies that a high-fiber, plant-rich diet may indirectly support C15 production by fueling the gut bacteria responsible for creating precursors.

C15:0 Sources: Plant vs. Animal vs. Supplement

To understand the best way to get C15, it helps to compare the primary sources and their characteristics.


Feature	Animal-Based Sources (Dairy)	Plant-Based Sources (Trace)	Vegan Supplements (Fatty15)
C15 Bioavailability	C15 is attached to lipids (triglycerides), requiring breakdown by the intestines for absorption, which can be less efficient.	Negligible; present only in trace amounts in certain foods like chia seeds.	Provides pure, free fatty acid form of C15:0, allowing for faster and more efficient absorption.
Associated Fats	High levels of other saturated fats (even-chain), which have been linked to negative health outcomes.	Can contain both beneficial unsaturated and other saturated fats, but C15 content is too low to be a reliable source.	Delivers only C15:0 without the unnecessary calories or other fats associated with animal-based sources.
Serving Size	Large quantities of whole-fat dairy products (e.g., 5 cups of milk or 7 oz cheese) are needed to reach modest C15 levels.	Impractically large quantities of plants would be required to get any significant amount of C15.	Typically delivered in a single, low-calorie capsule, providing a concentrated, reliable dose.
Vegan-Friendly	No, these are animal products.	Yes, but functionally irrelevant for meaningful intake.	Yes, specifically formulated for individuals on a plant-based diet.

How C15 Supplements Provide a Vegan Option

Because relying on diet alone for C15 is challenging for vegans, supplements have emerged as a practical solution. Vegan C15 supplements, such as Fatty15, are not extracted from plants that naturally contain C15 in small quantities. Instead, they are synthetically produced from plant-based fatty acids. The manufacturing process involves adding a single carbon atom to a C14:0 fatty acid precursor to create a pure C15:0 fatty acid.

This method offers several advantages for vegans and those seeking to increase their C15 levels without consuming animal products or other unhealthy fats:

Purity: These supplements provide a pure, concentrated form of C15:0.
Efficiency: The fatty acid is in a free, bioavailable form, bypassing the less efficient absorption process required for C15 found in dairy fat.
Targeted Intake: It allows for a specific, controlled dosage to help restore or maintain healthy C15 levels.

Conclusion: Navigating C15 on a Plant-Based Diet

While it is technically possible to find trace amounts of C15 in some plants, it is not a viable dietary source for obtaining meaningful levels. The most significant natural dietary sources are animal-based. Fortunately, those following a plant-based diet have alternative options to support their C15 levels, including both the body's natural synthesis pathways and targeted supplementation. A diet rich in fiber can enhance the body's endogenous production, while vegan-friendly C15 supplements offer a reliable, pure, and efficient way to ensure adequate intake of this emerging essential fatty acid.

For more in-depth information on the science behind C15:0, the manufacturer of the Fatty15 supplement provides comprehensive research resources on their dedicated informational site [discoverc15.com].

Frequently Asked Questions

Only trace amounts of C15 have been found in a small number of plants, such as peanuts, chia seeds, and certain species of Acacia. The concentration is too low for them to be a practical dietary source.

Yes, your body can synthesize C15 endogenously. Gut bacteria ferment dietary fiber to produce propionic acid, which your liver can then convert into C15.

Vegan C15 supplements are not extracted from natural plant sources. Instead, they are synthetically manufactured in a lab from a plant-based fatty acid precursor (C14:0), making them suitable for vegan diets.

While dairy contains C15, it is also high in other saturated fats (even-chain saturated fats) that are linked to negative health outcomes. Additionally, the C15 is less bioavailable than in a pure supplement.

No, studies have shown that blood levels of C15 are generally comparable in vegans, vegetarians, and omnivores, likely due to the body's ability to produce it internally.

For vegans, combining a high-fiber diet to support endogenous synthesis with a pure, vegan C15 supplement is the most effective way to ensure adequate intake.

While C15 shows great promise for health, the National Academies of Science, Engineering, and Medicine do not currently recognize it as an essential fatty acid. However, some researchers have proposed it as a candidate for this status.