Is fos profitable to sell on Amazon United States?

The niche generates $81K/yr across 15 tracked products. 90-day search growth is -15.8%. Flapen's verdict: Skip it (43/100).

How competitive is the fos niche?

10 brands and 27 sellers compete. The top 5 products take 70% of clicks and top 5 brands hold 84% of demand.

What do buyers complain about in fos?

Top complaints mined from reviews: Taste-Overall, Ingredients-Overall, Solubility. The return rate is 0.0%.

When does demand for fos peak?

Demand peaks in Aug–Dec; the busiest month runs 1.8× the quietest.

What does it cost to enter the fos niche?

Listings span $8.78–$31.56; the average listing price is $18.51 (sweet spot $15–$100). The average incumbent carries 968 reviews — the moat a new listing must climb.

fos

Skip it

Soft demand (-15.8% this quarter) — this niche doesn't clear our bar today.

Returns

Incredible0.0%

return rate — above 5% kills the launch gate

Avg price

Great$18.51

avg listing price — sweet spot $15–$100

Price range

Good$8.78–$31.56

cheapest to priciest tracked listing — scored on the share inside $15–$100

Review moat

Good968.4

avg incumbent reviews — the moat a new listing must climb

Quality gap

Okay4.5★

avg incumbent rating — lower means beatable quality

Conversion

Okay3.5%

search→purchase rate — share of searches ending in a sale

Brand share

Okay84%

top-5 brand share — brands hold most of the demand

Competition

Okay70%

top-5 click share — leaders hold, buyers still browse

Market size

Bad$81K

$81K/yr · 126K searches

Growth

Bad-15.8%

90-day search growth — must beat 0% to launch

Signals Low Review Barrier

According to Flapen's Amazon United States niche tracking, fos is a $81K/yr Amazon United States market (126K searches/yr). The top 5 brands hold 84% of demand. Demand peaks in Aug–Dec. Verdict: Skip it — 43/100.

Data updated Jul 25, 2026 · scored weekly · How we score niches

fos market data

Units sold / yr: 4K–5K; avg 250–500/product
Revenue / yr: $74K–$93K; units × avg price
Conversion rate: 3.5%
Avg BSR: #898
Page quality: 0%
Prime: 100%
Sponsored: 73%
Out of stock: 0.9%
Avg brand age: 72 months
Avg seller age: 153 days

Competition & brand share

The top 5 products take 70% of clicks — established leaders, but buyers still shop beyond them.

Brands

10 falling

Sellers

Top-5 brand share

84%

Top 20: 100%

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 & seasonality

Weekly Amazon search volume, last 98 weeks — -15.8% search growth over the last 90 days.

Peak months: Aug, Dec · busiest ÷ quietest = 1.8×

Open Trend

Top fos search terms

fos91K/yr -2.7%0.9% conv.
fructooligosaccharides11K/yr -33.8%6.3% conv.
fos powder10K/yr -39.7%10.7% conv.
fos powder organic4K/yr -20.8%9.9% conv.
fos supplement3K/yr -46.1%7.8% conv.
fructooligosaccharides powder3K/yr -51.6%10.2% conv.
fructooligosaccharide2K/yr -74.3%3.0% conv.
fructooligosaccharides prebiotic2K/yr -84.2%0.0% conv.

All search terms

Top fos products on Amazon

Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 15 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

NOW Foods Supplements NutraFlora FOS (Fructooligosaccharides) Pure Powder Prebiotic Fiber 4-Ounce

NOW Foods$11.634.5★341 rev

Supersmart Fructo Oligosaccharides Powder (Prebiotics FOS) - Oligofructose Inulin - Fiber Supplement | Non-GMO & Gluten Free - 200 g

Supersmart$17.174.3★93 rev

Pure Original Ingredients Fructooligosaccharides 4oz No Additives FOS Powder

PURE ORIGINAL INGREDIENTS$9.884.5★116 rev

Micro Ingredients Organic Inulin FOS Fiber Powder 2.2 lbs | Quick Water-Soluble Prebiotic | Natural Fiber for Smoothies & Drinks | Vegan Friendly Dissolves Clear

Micro Ingredients$29.924.6★5,239 rev

Perfect Gut: Inulin FOS Powder for Gut Health. Prebiotic Inulin. Unique Prebiotic 95% FOS Agave Fiber

Kidney Restore$31.564.4★139 rev

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

Micro Ingredients$19.725,239 rev

1y ago

Nutricost Prebiotic Fiber Unflavored (1 Pound) Gluten Free

Nutricost$19.62251 rev

1y ago

Perfect Gut: Inulin FOS Powder for Gut Health. Prebiotic Inulin. Unique Prebiotic 95% FOS Agave Fiber

Kidney Restore$31.56139 rev

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

Micro Ingredients$13.26289 rev

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

Natural Flow Supplements$26.20500 rev

3y ago

What buyers say about fos

What buyers praise and complain about, mined from review topics.

What buyers love

Quality-Overall13%

“Excellent product”

Solubility11%

“The powder mixes well”

Nutritional Content11%

“I believe it's a good overall probiotic”

Regulates Digestion9%

“it completely cleared up my constipation which had been a problem on”

Value For Money7%

“Good price”

Taste-Overall7%

“Good taste and healthy”

Efficiency5%

“Works well”

Sweetness4%

“It has a mild sweet flavor”

Advertised Vs Actual Product4%

“As advertised”

Flavor2%

“enjoy without affecting their flavor”

What buyers complain about

Taste-Overall8%

“I cant taste in water”

Ingredients-Overall7%

“not the bag's ingredients list”

Solubility5%

“I don't like that it dissolves well in water”

Side Effects5%

“This product gives HORRIBLE GAS”

Advertised Vs Actual Product4%

“I don't appreciate deceptive product description”

Nutritional Content4%

“There are not enough carbs or calories for this product to contain whole milk powder”

Dosage4%

“the amount is too much for me”

Acid Regulator/Stomach Ache Relief3%

“and my stomach told me that it was way too much”

Functionality-Overall3%

“Doesnt work”

Regulates Digestion3%

“I don't recommend it to people with digestive problems”

Top return reasons

Functionality-Overall40%

Advertised Vs Actual Product20%

Artificial Sweeteners20%

Acid Regulator/Stomach Ache Relief20%

Common questions

Is fos profitable to sell on Amazon United States?: The niche generates $81K/yr across 15 tracked products. 90-day search growth is -15.8%. Flapen's verdict: Skip it (43/100).
How competitive is the fos niche?: 10 brands and 27 sellers compete. The top 5 products take 70% of clicks and top 5 brands hold 84% of demand.
What do buyers complain about in fos?: Top complaints mined from reviews: Taste-Overall, Ingredients-Overall, Solubility. The return rate is 0.0%.
When does demand for fos peak?: Demand peaks in Aug–Dec; the busiest month runs 1.8× the quietest.
What does it cost to enter the fos niche?: Listings span $8.78–$31.56; the average listing price is $18.51 (sweet spot $15–$100). The average incumbent carries 968 reviews — the moat a new listing must climb.

fos

fos market data

Competition & brand share

Demand & seasonality

Top fos search terms

Top fos products on Amazon

Top sellers

Newest

Trending

What buyers say about fos

What buyers love

What buyers complain about

Top return reasons

Common questions

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