glycine
Worth a lookShows low returns (0.1%), but soft demand (-22.8% this quarter) keeps it on the watch list.
Returns
Incredible0.1%return rate — above 5% kills the launch gate
Conversion
Incredible13.6%search→purchase rate — share of searches ending in a sale
Review moat
Good568.23avg incumbent reviews — the moat a new listing must climb
Market size
Good£316K£316K/yr · 198K searches
Avg price
Okay£11.72avg listing price — sweet spot $15–$100
Brand share
Okay78%top-5 brand share — brands hold most of the demand
Quality gap
Okay4.5★avg incumbent rating — lower means beatable quality
Price range
Okay£3.97–£21.83cheapest to priciest tracked listing — scored on the share inside $15–$100
Competition
Bad75%top-5 click share — a locked-up shelf
Growth
Bad-22.8%90-day search growth — must beat 0% to launch
According to Flapen's Amazon United Kingdom niche tracking, glycine is a £316K/yr Amazon United Kingdom market (198K searches/yr). The top 5 brands hold 78% of demand. Verdict: Worth a look — 50/100.
Data updated Jul 24, 2026 · scored weekly · How we score niches
glycine market data
- Units sold / yr
- 20K–25K
- avg 1,250–1,500/product
- Revenue / yr
- £234K–£293K
- units × avg price
- Conversion rate
- 13.6%
- Avg BSR
- #194
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 77%
- Out of stock
- 0.8%
- Avg brand age
- 44 months
- Avg seller age
- 173 days
Competition & brand share
The top 5 products capture 75% of clicks — a locked-up shelf that new listings rarely crack.Brands
11 falling
Sellers
15
Top-5 brand share
78%
Top 20: 100%
Top-5 click share
75%
Top 20: 100%
Open market
16%
- Bulk32%
- NEW LEAF PRODUCTS18%
- ALPHA0114%
- THORNE8%
- Peak Supps7%
- Vegavero7%
- Open — no brand owns it (5 brands, 16%)
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -22.8% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 2.0×
Top glycine search terms
- glycine164K/yr
- glycine supplement11K/yr
- l-glycine8K/yr
- l glycine5K/yr
- glycine 3g7K/yr
- glycin2K/yr
Top glycine 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.
All 13 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Bulk Glycine Powder 500 g
Bulk£3.974.6★822 rev
L-Glycine Capsules - 180 High Strength Vegan Amino Acid Suppelements - 1600mg Per Serving Providing A 3 Month Supply - Glycine Supplement Made in The UK By New Leaf
NEW LEAF PRODUCTS£8.174.3★100 rev
Fermented L Glycine 1500mg with BioPerine 180 Vegan Capsules High Strength L Glycine Amino Acid Supplement Resealable and Recyclable Pouch By Alpha01
ALPHA01£7.334.4★139 rev
Thorne Glycine 250 Capsules
THORNE£21.834.7★1,430 rev
Vegavero Pure Glycine Powder 1 kg | 3000 mg Daily Dose | NO Additives Lab-Tested | Recovery Muscle & Collagen Synthesis | with Measuring Spoon | Vegan
Vegavero£18.004.5★2,394 rev
Newest
by launch date
LALEA Pure Glycine Powder 500g 100% Pure L-Glycine Amino Acid Supplement Vegan No Additives Highly Soluble Supports Sleep Muscle Recovery & Collagen Production
lalea£8.07306 rev
L-Glycine Capsules - 180 High Strength Vegan Amino Acid Suppelements - 1600mg Per Serving Providing A 3 Month Supply - Glycine Supplement Made in The UK By New Leaf
NEW LEAF PRODUCTS£8.17100 rev
Vitamatic Glycine Supplement 2000mg Per Serving 300 Count Non-GMO Gluten Free
Vitamatic£16.12201 rev
Now Foods Glycine 1000mg 100 Vegan Capsules Amino Acid Gluten Free Vegetarian Soy Free Non GMO
NOW£19.1486 rev
L Glycine Supplement 1500mg | 180 Vegan Tablets | Amino Acid Nutritional Supplements | by Horbaach
Horbäach£7.17251 rev
Trending
90-day click momentumLALEA Pure Glycine Powder 500g 100% Pure L-Glycine Amino Acid Supplement Vegan No Additives Highly Soluble Supports Sleep Muscle Recovery & Collagen Production
lalea£8.074.5★
Bulk Glycine Powder 500 g
Bulk£3.974.6★
Vitamatic Glycine Supplement 2000mg Per Serving 300 Count Non-GMO Gluten Free
Vitamatic£16.124.6★
L-Glycine Capsules - 180 High Strength Vegan Amino Acid Suppelements - 1600mg Per Serving Providing A 3 Month Supply - Glycine Supplement Made in The UK By New Leaf
NEW LEAF PRODUCTS£8.174.3★
Thorne Glycine 250 Capsules
THORNE£21.834.7★
What buyers say about glycine
What buyers praise and complain about, mined from review topics.What buyers love
“Helps me sleep”
“Excellent product”
“Good value for money”
“Tastes nice as well”
“Mixes easily”
“The taste is naturally sweet and pleasant”
“* Vegan-friendly. unlike collagen itself”
“found it straightforward to take”
“it does have a calming feel”
“pure gives me peace of mind about the quality of the ingredients I am putting into my body”
What buyers complain about
“not much difference to sleep quality”
“Apart from that some capsules are half empty”
“Utterly deceptive”
“serious side effects are possible”
“Bad quality”
“Doesn't work for everyone”
“They are absolutely massive”
“This one has zero taste”
“I stopped using them as a smell of sulphur was coming off me which I didn't like”
“Not for an over active mind”
Top return reasons
Common questions
- Is glycine profitable to sell on Amazon United Kingdom?
- The niche generates £316K/yr across 13 tracked products. 2 of 3 products launched in the last 360 days are still selling. 90-day search growth is -22.8%. Flapen's verdict: Worth a look (50/100).
- How competitive is the glycine niche?
- 11 brands and 15 sellers compete. The top 5 products take 75% of clicks and top 5 brands hold 78% of demand.
- What do buyers complain about in glycine?
- Top complaints mined from reviews: Sleep Quality, Dosage, Advertised Vs Actual Product. The return rate is 0.1%.
- When does demand for glycine peak?
- Demand is steady year-round — the busiest month runs 2.0× the quietest.
- What does it cost to enter the glycine niche?
- Listings span £3.97–£21.83; the average listing price is £11.72 (sweet spot $15–$100). The average incumbent carries 568 reviews — the moat a new listing must climb.