Is glycine 3g profitable to sell on Amazon United States?

The niche generates $171K/yr across 16 tracked products. 3 of 3 products launched in the last 360 days are still selling. 90-day search growth is -34.4%. Flapen's verdict: Skip it (48/100).

How competitive is the glycine 3g niche?

13 brands and 31 sellers compete. The top 5 products take 69% of clicks and top 5 brands hold 75% of demand.

What do buyers complain about in glycine 3g?

Top complaints mined from reviews: Sleep Quality, Functionality-Overall, Dosage. The return rate is 0.0%.

When does demand for glycine 3g peak?

Demand peaks in Jan–Feb–Mar–Dec; the busiest month runs 3.8× the quietest.

What does it cost to enter the glycine 3g niche?

Listings span $9.89–$33.21; the average listing price is $19.46 (sweet spot $15–$100). The average incumbent carries 1,544 reviews — the moat a new listing must climb.

glycine 3g

Skip it

Soft demand (-34.4% this quarter) — this niche doesn't clear our bar today.

Returns

Incredible0.0%

return rate — above 5% kills the launch gate

Conversion

Great10.9%

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

Avg price

Great$19.46

avg listing price — sweet spot $15–$100

Price range

Great$9.89–$33.21

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

Brand share

Good75%

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

Review moat

Okay1,544.38

avg incumbent reviews — the moat a new listing must climb

Market size

Okay$171K

$171K/yr · 81K searches

Quality gap

Okay4.6★

avg incumbent rating — lower means beatable quality

Competition

Okay69%

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

Growth

Bad-34.4%

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

According to Flapen's Amazon United States niche tracking, glycine 3g is a $171K/yr Amazon United States market (81K searches/yr). The top 5 brands hold 75% of demand. Demand peaks in Jan–Feb–Mar–Dec. Verdict: Skip it — 48/100.

Data updated Jul 10, 2026 · scored weekly · How we score niches

glycine 3g market data

Units sold / yr: 10K–13K; avg 500–750/product
Revenue / yr: $195K–$243K; units × avg price
Conversion rate: 10.9%
Avg BSR: #751
Page quality: 0%
Prime: 100%
Sponsored: 88%
Out of stock: 2.9%
Avg brand age: 63 months
Avg seller age: 188 days

Competition & brand share

The top 5 products take 69% of clicks — established leaders, but buyers still shop beyond them.

Brands

13 rising

Sellers

Top-5 brand share

75%

Top 20: 100%

Top-5 click share

69%

Top 20: 100%

Open market

17%

Pure Encapsulations26%
THORNE16%
BulkSupplements13%
NOW Foods11%
Nutricost9%
Life Extension8%
Open — no brand owns it (7 brands, 17%)

Demand & seasonality

Weekly Amazon search volume, last 53 weeks — -34.4% search growth over the last 90 days.

Peak months: Jan, Feb, Mar, Dec · busiest ÷ quietest = 3.8×

Open Trend

Top glycine 3g 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 16 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

Pure Encapsulations Glycine - Supports Restful Sleep & Liver Detox* - Liver Supplement - Vegan & Gluten-Free - 180 Capsules

Pure Encapsulations$33.214.6★903 rev

THORNE - Glycine - Supports Relaxation Stress Management Detoxification & Healthy Muscle Function* - Amino Acid Supplement - Third-Party Certified - Gluten Dairy & Soy-Free - 250 Capsules

THORNE$30.064.6★1,452 rev

BulkSupplements.com Glycine Capsules - Amino Acid Supplement 3000mg - Gluten Free 4 Capsules per Serving 360 Count (Pack of 1)

BulkSupplements$20.814.4★719 rev

Nutricost Glycine Powder 1lb - Non-GMO Gluten Free

Nutricost$21.754.6★1,555 rev

Life Extension Glycine 1000 mg Amino Acid that Promotes Healthy Sleep Gluten-Free Non-GMO Vegetarian 100 Capsules

Life Extension$11.594.6★3,334 rev

Newest

by launch date

Innate Vitality Glycine Supplements 3000mg per Serving Bioavailable Form Sleep Relax Collagen Glutathione Production Non-GMO Conditionally Essential Amino Acids Vegan 240 Capsules

Innate Vitality$24.9544 rev

5mo ago

HOLLEGEND Glycine 3g Gummies Organic L-Glycine with NAC Supplements for Sleep & Cellular Support Plus B6 L-Theanine & Taurine for Nerve Liver Detox & Immune Health Sugar Free Vegan 60 Chews

HOLLEGEND$21.6654 rev

6mo ago

duwhot Glycine Gummies 3g(3000 mg) Glycine Supplements for Sleep Detox Relax Nerve Support Blueberry Flavor Sugar-Free Vegan Non-GMO Gluten-Free 60 Ct.

duwhot$20.78113 rev

8mo ago

Glycine 2 000mg Per Serving 240 Veggie Capsules | Free Form | Double Strength Amino Acids | Restful Sleep and Neurotransmitter Support Supplements | Non-GMO Gluten Free

Micro Ingredients$15.93245 rev

1y ago

Puregen Labs Glycine 1000mg [High Potency] 100 Vegetarian Capsules Promotes Healthy Rest | No Harmful Additives | Non-GMO NO Gluten and Dairy -100 Servings

P Puregen Labs$9.89545 rev

1y ago

What buyers say about glycine 3g

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

What buyers love

Sleep Quality29%

“Helps me sleep”

Quality-Overall12%

“Quality products Good price Quick Delivery”

Value For Money5%

“Great value”

Taste-Overall5%

“no funky aftertaste”

Vitamin4%

“Good quality vitamins”

Solubility2%

“It dissolves super easily”

Sweetness2%

“Tastes slightly sweet”

Nutritional Content2%

“Best Supplement Out There”

Dosage2%

“with a good amount per capsule”

Stress/Anxiety2%

“Effective in reducing stress”

What buyers complain about

Sleep Quality19%

“Did not help with sleep”

Functionality-Overall8%

“Didn't work for me”

Dosage6%

“The dosage is not clearly listed on the sales page”

Quality-Overall6%

“Poor Quality Control”

Solubility5%

“Does not dissolve”

Taste-Overall4%

“Completely different taste”

Side Effects4%

“Now I have dizziness and vertigo”

Smell4%

“Chemical Smell”

Value For Money2%

“Too Expensive - glycine is glycine”

Stress/Anxiety2%

“My next day was wrecked with exhaustion”

Top return reasons

Sleep Quality24%

Functionality-Overall18%

Dosage12%

Hard Feel6%

Advertised Vs Actual Product6%

Muscle Pain Relief6%

Blood Sugar Level6%

Acid Regulator/Stomach Ache Relief6%

Calcium6%

Adhesion/Stickiness6%

Common questions

Is glycine 3g profitable to sell on Amazon United States?: The niche generates $171K/yr across 16 tracked products. 3 of 3 products launched in the last 360 days are still selling. 90-day search growth is -34.4%. Flapen's verdict: Skip it (48/100).
How competitive is the glycine 3g niche?: 13 brands and 31 sellers compete. The top 5 products take 69% of clicks and top 5 brands hold 75% of demand.
What do buyers complain about in glycine 3g?: Top complaints mined from reviews: Sleep Quality, Functionality-Overall, Dosage. The return rate is 0.0%.
When does demand for glycine 3g peak?: Demand peaks in Jan–Feb–Mar–Dec; the busiest month runs 3.8× the quietest.
What does it cost to enter the glycine 3g niche?: Listings span $9.89–$33.21; the average listing price is $19.46 (sweet spot $15–$100). The average incumbent carries 1,544 reviews — the moat a new listing must climb.