- Flapen Score
- 43 / 100Ranks 10,775 of 14,768 Health & Household niches · −6 vs the category median of 4943
- Market size
- $81K/yr126K searches / yr
- 90-day growth
- -15.8%search demand this quarter
- Competition
- 70%top-5 click share · 10 brands · 27 sellers
Flapen Score
Fos against its category
The dotted line is the Health & Household average. Past it, Fos is stronger. Inside it, weaker.
Market
The Fos market on Amazon at a glance
Shoppers on Amazon United States searched for Fos 126K times last year and spent an estimated $81K. The top 5 brands take 84% of clicks. Demand peaks in Aug–Dec. Flapen scores it 43 out of 100, a Fail.
01 · Demand
An estimated 3.5% of those searches ended in a purchase.
Shoppers searched for this 126K times in the last 12 months. That counts every search on Amazon United States for this niche's terms. An estimated 3.5% of those searches ended in a purchase. Searches in the last 90 days moved -15.8% against the 90 days before. Searches, conversion and average price together put the market at an estimated $81K a year.
- Searches, last 12 months
- 126K
- Growth, 90 days vs prior 90
- -15.8%
- Conversion, latest week
- 3.5%
- Market size, estimated
- $81Ka year
- Peak month
- December1.8× the quietest month
- Top search term
- fos91K searches a year
02 · Price
A sale here is worth $18.51.
Listings sell for $18.51 on average, from $8.78 to $31.56. Amazon reports units sold in ranges. This niche sold 4K to 5K a year. The average listing sells 250 to 500 of them. At $18.51 that is $5K to $9K a year per listing.
- Average price
- $18.51inside the $15 to $100 sweet spot
- Price range
- $8.78–$31.56
- Amazon United States median price
- $24.38across 115,062 niches
- Units sold a year
- 4K–5K
- Units per listing a year
- 250–500
- Revenue per listing a year
- $5K–$9K
- Returns
- 0.0%of orders · Amazon United States median 2.1%
03 · Entry bar
The bar here is low.
73% of listings pay for placement with sponsored ads. 100% ship with Prime. On an average day, 0.9% of listings are out of stock. The average listing ranks #898 within Digestive Supplements. It carries 968 reviews at 4.47 stars, so a new listing needs social proof before a better product.
- Sponsored listings
- 73%
- Prime listings
- 100%
- Out of stock, average day
- 0.9%
- Average rank
- #898in Digestive Supplements
- Average rating
- 4.47 starsAmazon United States average 4.42 stars
- Average reviews
- 968per listing
- Listings tracked
- 15
04 · Newcomers
Brands here are established.
The brands on the shelf have sold for 72 months on average, so the names here are established.
- Launched, last 12 months
- 0
- Successful launches
- 0Amazon's first-year sales bar
- Average brand age
- 72 months
Products
Top Fos products & what they sell for
The products selling here, as shoppers see them on Amazon. Shelf share and sales are our estimates.
Prices and ratings read from Amazon on Jul 25, 2026. The live listing can differ.
Top sellers
by estimated 90-day click share
NOW Foods Supplements NutraFlora FOS (Fructooligosaccharides) Pure Powder Prebiotic Fiber 4-Ounce
- Price
- $11.63
- Rating
- 4.5/5
- Reviews
- 341
- Age
- 19y ago

Supersmart Fructo Oligosaccharides Powder (Prebiotics FOS) - Oligofructose Inulin - Fiber Supplement | Non-GMO & Gluten Free - 200 g
- Price
- $17.17
- Rating
- 4.3/5
- Reviews
- 93
- Age
- 10y ago

Pure Original Ingredients Fructooligosaccharides 4oz No Additives FOS Powder
- Price
- $9.88
- Rating
- 4.5/5
- Reviews
- 116
- Age
- 4y ago

Micro Ingredients Organic Inulin FOS Fiber Powder 2.2 lbs | Quick Water-Soluble Prebiotic | Natural Fiber for Smoothies & Drinks | Vegan Friendly Dissolves Clear
- Price
- $29.92
- Rating
- 4.6/5
- Reviews
- 5,239
- Age
- 9y ago

Perfect Gut: Inulin FOS Powder for Gut Health. Prebiotic Inulin. Unique Prebiotic 95% FOS Agave Fiber
- Price
- $31.56
- Rating
- 4.4/5
- Reviews
- 139
- Age
- 1y ago
Trending
estimated 90-day click momentum
Sprout Living Organic Inulin with FOS Prebiotic Powder Soluble Fiber for Leaky Gut Bloating Digestion Feed Friendly Bacteria (Probiotics) 1 Scoop Daily 1 lb (90 Servings)
- Price
- $19.76
- Rating
- 4.7/5
- Reviews
- 515
- Age
- 8y ago

Swanson Prebiotic Fiber Capsules with NutraFlora FOS for Gut-Health-Conscious Adults Seeking Digestive Flora and Immune Support - 750 mg (120 Vegan Capsules)
- Price
- $15.86
- Rating
- 4.6/5
- Reviews
- 1,011
- Age
- 9y ago

Micro Ingredients Organic Inulin FOS Fiber Powder 1.1 lb | Quick Water-Soluble Prebiotic | Natural Unflavored Fiber for Yogurt Smoothies & Drinks | Vegan Friendly Dissolves Clear Non-GMO
- Price
- $19.72
- Rating
- 4.6/5
- Reviews
- 5,239
- Age
- 1y ago

Nutricost Prebiotic Fiber Unflavored (1 Pound) Gluten Free
- Price
- $19.62
- Rating
- 4.5/5
- Reviews
- 251
- Age
- 1y ago

Prebiotic Fiber Supplement 5-in-1 Capsules - Natural Flow 5X Fiber XOS GOS FOS Acacia and Agave Inulin Daily Soluble Fiber Formula for Gut Support and Boost Good Bacteria Diversity 120 Caps
- Price
- $26.20
- Rating
- 4.5/5
- Reviews
- 500
- Age
- 3y ago
Newest
by launch date
Micro Ingredients Organic Inulin FOS Fiber Powder 1.1 lb | Quick Water-Soluble Prebiotic | Natural Unflavored Fiber for Yogurt Smoothies & Drinks | Vegan Friendly Dissolves Clear Non-GMO
- Price
- $19.72
- Rating
- 4.6/5
- Reviews
- 5,239
- Age
- 1y ago

Nutricost Prebiotic Fiber Unflavored (1 Pound) Gluten Free
- Price
- $19.62
- Rating
- 4.5/5
- Reviews
- 251
- Age
- 1y ago

Perfect Gut: Inulin FOS Powder for Gut Health. Prebiotic Inulin. Unique Prebiotic 95% FOS Agave Fiber
- Price
- $31.56
- Rating
- 4.4/5
- Reviews
- 139
- Age
- 1y ago

Micro Ingredients Vitality Prebiotic Fiber Powder 1lb | Easy Mix Powder for Digestive & Gut Health | Daily Prebiotic Soluble Fiber Supplement for Women and Men | Unflavored Sugar Free & Vegan
- Price
- $13.26
- Rating
- 4.4/5
- Reviews
- 289
- Age
- 1y ago

Prebiotic Fiber Supplement 5-in-1 Capsules - Natural Flow 5X Fiber XOS GOS FOS Acacia and Agave Inulin Daily Soluble Fiber Formula for Gut Support and Boost Good Bacteria Diversity 120 Caps
- Price
- $26.20
- Rating
- 4.5/5
- Reviews
- 500
- Age
- 3y ago
Competition
Competition: brands, sellers & click share
The top 5 products take an estimated 70% of clicks. Leaders hold, but buyers still shop past them.
Brands
10 falling
Sellers
27
Est. top-5 brand share
84%
Top 20: 100%
Est. top-5 click share
70%
Top 20: 100%
Open market
10%
- NOW Foods22%
- PURE ORIGINAL INGREDIENTS18%
- Supersmart18%
- Micro Ingredients17%
- Source Naturals10%
- Kidney Restore7%
- Open — no brand owns it (4 brands, 10%)
Demand
Fos search demand
Weekly searches over the year, seasonality beneath. Pick a range.
Peak months: Aug, Dec · busiest ÷ quietest = 1.8×
Search terms
Top Fos search terms shoppers use
The exact words shoppers type, with estimated yearly volume, growth, and conversion.
- fos91K/yr
- fructooligosaccharides11K/yr
- fos powder10K/yr
- fos powder organic4K/yr
- fos supplement3K/yr
- fructooligosaccharides powder3K/yr
- fructooligosaccharide2K/yr
- fructooligosaccharides prebiotic2K/yr
Reviews and returns
What reviews say buyers love and hate about Fos
We read the reviews and the return reasons for every product selling here.
“I cant taste in water”
Every topic
Every topic buyers talk about, one row each.
Red shows the share of negative reviews and green the share of positive reviews, biggest topic first. Open a row to read what they wrote.
16 topics
Keep looking
Related niches
Niches in the same category that score near this one. Research these next.
Best Flapen score
The highest-scoring niches we track right now, across every category.
FAQ
Common Fos questions
Answered from the same tracked data.
Figures on this page are estimates modeled from public Amazon pages and third-party keyword data. Amazon does not supply them, and no connected seller's data is used. How we handle Amazon data









