FOS (Fructooligosaccharides)

Generally Safe FillerNatural

FOS (Fructooligosaccharides) is a naturally derived filler used in dietary supplements. Safety rating: Generally Safe. It is generally considered safe for most people at standard doses. Found in 20 supplements in the GoodSupp database. A type of prebiotic fiber that promotes gut health.

20 Products use this
Generally Safe Safety rating
Filler Category
Yes Natural origin

Safety Verdict: Generally Safe

May cause gas and bloating in some individuals.

What is FOS (Fructooligosaccharides)?

A type of prebiotic fiber that promotes gut health.

Common Names FOS (Fructooligosaccharides), Fructooligosaccharides
Type Filler
Origin Natural / Plant-derived
Safety Rating Generally Safe

Why is FOS (Fructooligosaccharides) used in supplements?

It is used as a filler and to support digestive health.

Role in supplements: Filler — adds bulk to fill capsules or tablets to a standard size. Does not contribute to the supplement's active benefits.

Should you be concerned about FOS (Fructooligosaccharides)?

Generally no. FOS (Fructooligosaccharides) is considered safe for most people at typical supplement doses. Some individuals may want to be aware of minor sensitivities.

May cause gas and bloating in some individuals.

Low risk. Generally safe for most people in supplement amounts.

Top-rated products containing FOS (Fructooligosaccharides)

These 20 highest-scoring supplements in our database use FOS (Fructooligosaccharides).

NOW Foods Probiotic-10™ & Bifido Boost™, 90 Veg Capsules
NOW Foods Probiotic-10™ & Bifido Boost™, 90 Veg Capsules
Product 100 Brand N/A
Protocol For Life Balance E.N.T. Biotic™, 60 Lozenges
Protocol For Life Balance E.N.T. Biotic™, 60 Lozenges
Product 100 Brand N/A
Protocol For Life Balance Protodophilus, 100 billion, 30 Veg Capsules
Protocol For Life Balance Protodophilus, 100 billion, 30 Veg Capsules
Product 100 Brand N/A
NOW OralBiotic, 60 Lozenges
NOW OralBiotic, 60 Lozenges
Product 100 Brand N/A
NOW NOW Supplements Probiotic-10 TM 25 Billion Vegetable Capsules, 50 Count
NOW NOW Supplements Probiotic-10 TM 25 Billion Vegetable Capsules, 50 Count
Product 95 Brand N/A
NOW Foods Probiotic-10™, 100 Veg Capsules
NOW Foods Probiotic-10™, 100 Veg Capsules
Product 93 Brand N/A
NOW Foods Probiotic-10™, 50 Billion, 50 Veg Capsules
NOW Foods Probiotic-10™, 50 Billion, 50 Veg Capsules
Product 93 Brand N/A
NOW Foods Probiotic-10™ 25 Billion, 50 Veg Capsules
NOW Foods Probiotic-10™ 25 Billion, 50 Veg Capsules
Product 93 Brand N/A
NOW Foods Probiotic-10™, 100 Billion, 60 Veg Capsules
NOW Foods Probiotic-10™, 100 Billion, 60 Veg Capsules
Product 93 Brand N/A
NOW Foods Probiotic-10™, 30 Veg Capsules
NOW Foods Probiotic-10™, 30 Veg Capsules
Product 93 Brand N/A
Protocol For Life Balance ProtoDophilus, 25 billion, 50 Veg Capsules
Protocol For Life Balance ProtoDophilus, 25 billion, 50 Veg Capsules
Product 93 Brand N/A
Natural Factors Ultimate Probiotic 24 Billion, 60 Vegetarian Capsules
Natural Factors Ultimate Probiotic 24 Billion, 60 Vegetarian Capsules
Product 90 Brand N/A
NOW NOW Supplements Gr8-Dophilus Capsules, 60 Count
NOW NOW Supplements Gr8-Dophilus Capsules, 60 Count
Product 88 Brand N/A
Protocol For Life Balance Ortho Dophilus™, 60 Veg Capsules
Protocol For Life Balance Ortho Dophilus™, 60 Veg Capsules
Product 87 Brand N/A
Natural Factors Ultimate Probiotic, 12/12 Formula, 12 Billion CFU, 120 Vegetarian Capsules
Natural Factors Ultimate Probiotic, 12/12 Formula, 12 Billion CFU, 120 Vegetarian Capsules
Product 86 Brand N/A
NOW Foods Gr8-Dophilus™, 60 Veg Capsules
NOW Foods Gr8-Dophilus™, 60 Veg Capsules
Product 83 Brand N/A
NOW Gr8-Dophilus, 120 VegCaps
NOW Gr8-Dophilus, 120 VegCaps
Product 83 Brand N/A
VITABURST The Smurfs Kids Probiotic Gummies with 1 Billion CFU Probiotics & Prebiotics Chewable Probiotic Kids for Digestive Support, Healthy Gut & Immune Health | Ages 3+ | Made with Real Fruit | 40 Count
VITABURST The Smurfs Kids Probiotic Gummies with 1 Billion CFU Probiotics & Prebiotics Chewable Probiotic Kids for Digestive Support, Healthy Gut & Immune Health | Ages 3+ | Made with Real Fruit | 40 Count
Product 83 Brand N/A
Action Labs Saw Palmetto+ For Men - Positive Prostate, 100 VegCaps
Action Labs Saw Palmetto+ For Men - Positive Prostate, 100 VegCaps
Product 77 Brand N/A
NOW NOW Supplements, Kids Probiotic (formerly BerryDophilus™) with 2 Billion, 10 Probiotic Strains, Xylitol Sweetened, Strain Verified, Chewable Tablets, 60 Count
NOW NOW Supplements, Kids Probiotic (formerly BerryDophilus™) with 2 Billion, 10 Probiotic Strains, Xylitol Sweetened, Strain Verified, Chewable Tablets, 60 Count
Product 77 Brand N/A
Related Ingredients
Almond Butter Generally Safe Almonds Generally Safe Apple Fiber Safe Broccoli Safe Brown Rice Generally Safe Brown Rice Flour Safe Brown Rice Protein Generally Safe Buttermilk Powder Generally Safe
Frequently Asked Questions
Is FOS (Fructooligosaccharides) safe in supplements?

FOS (Fructooligosaccharides) is rated generally safe for most people at amounts commonly found in supplements. While the overall safety profile is favorable, some individuals may experience minor sensitivities. May cause gas and bloating in some individuals. In GoodSupp's database, 20 products contain this ingredient. Consult your healthcare provider if you have specific concerns.

What is FOS (Fructooligosaccharides) and why is it in my supplement?

A type of prebiotic fiber that promotes gut health. As a filler, it adds bulk to capsules or tablets to achieve a standard size without affecting the active ingredients. It appears in 20 products in the GoodSupp database.

Is FOS (Fructooligosaccharides) natural or synthetic?

FOS (Fructooligosaccharides) is naturally derived, meaning it comes from natural sources such as plants, minerals, or animal products rather than being chemically synthesized. Natural-origin ingredients are preferred by many consumers, though it's important to note that 'natural' does not automatically mean 'safer' — safety depends on the specific substance, its purity, and the amount used. The safety rating assigned by GoodSupp is based on the ingredient's actual safety profile, not its origin.

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Disclaimer: GoodSupp provides independent supplement quality analysis for informational purposes only. Scores are generated algorithmically based on ingredient profiles, brand certifications, and public records. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Product data is sourced from manufacturer labels and public databases. GoodSupp is not affiliated with any supplement brand.