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Glycine

Maybe

Returns run at only 0.1% of orders. But demand is soft, at -22.8% this quarter, so Glycine is a Maybe.

Flapen Score
50
50 / 100
Top 41% of 2,035 Health & Personal Care niches · +2 vs the category median of 48
Market size
£316K/yr198K searches / yr
90-day growth
-22.8%search demand this quarter
Competition
75%top-5 click share · 11 brands · 15 sellers

Flapen Score

Glycine against its category

The dotted line is the Health & Personal Care average. Past it, Glycine is stronger. Inside it, weaker.

50Maybe
Big MarketTrendingHigh ConversionOpen MarketLow ReturnsPrice rangeAvg priceNo Dominant BrandLow Review BarrierQuality Gap
This niche Category average

Market

The Glycine market on Amazon at a glance

Shoppers on Amazon United Kingdom searched for Glycine 198K times last year and spent an estimated £316K. The top 5 brands take 78% of clicks. Flapen scores it 50 out of 100, a Maybe.

01 · Demand

13.6% of searches ended in a purchase last week.

Shoppers searched for this 198K times in the last 12 months. That counts every search on Amazon United Kingdom for this niche's terms. In the latest week, 13.6% of those searches ended in a purchase. Searches in the last 90 days moved -22.8% against the 90 days before. Searches, conversion and average price together put the market at an estimated £316K a year.

Searches, last 12 months
198K
Growth, 90 days vs prior 90
-22.8%
Conversion, latest week
13.6%
Market size, estimated
£316Ka year
Peak month
February2.0× the quietest month
Top search term
glycine164K searches a year

02 · Price

A sale here is worth £11.72.

Listings sell for £11.72 on average, from £3.97 to £21.83. Amazon reports units sold in ranges. This niche sold 20K to 25K a year. The average listing sells 1,250 to 1,500 of them. At £11.72 that is £15K to £18K a year per listing.

Average price
£11.72under the $15 to $100 sweet spot
Price range
£3.97–£21.83
Amazon United Kingdom median price
£12.12across 27,606 niches
Units sold a year
20K–25K
Units per listing a year
1,250–1,500
Revenue per listing a year
£15K–£18K
Returns
0.1%of orders · Amazon United Kingdom median 0.6%

03 · Entry bar

The bar here is low.

77% of listings pay for placement with sponsored ads. 100% ship with Prime. On an average day, 0.8% of listings are out of stock. The average listing ranks #194 within Diet & Nutrition. It carries 568 reviews at 4.48 stars, so a new listing needs social proof before a better product.

Sponsored listings
77%
Prime listings
100%
Out of stock, average day
0.8%
Average rank
#194in Diet & Nutrition
Average rating
4.48 starsAmazon United Kingdom average 4.36 stars
Average reviews
568per listing
Listings tracked
13

04 · Newcomers

Amazon counts 2 of last year's 3 launches as successful.

3 products launched here in the last 12 months. Amazon counts 2 of them as successful launches, new products that hit its first-year sales bar. The brands on the shelf have sold for 44 months on average, so the names here are settling in.

Launched, last 12 months
3
Successful launches
2Amazon's first-year sales bar
Average brand age
44 months

Products

Top Glycine products & what they sell for

Every tracked product: its share of the shelf, its reviews, and its price.

Competition

Competition: brands, sellers & click share

The top 5 products take 75% of clicks. A locked shelf that new listings rarely crack.

£0£32K£63K£95K£126K101001K10K Review Count Sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

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

Glycine search demand

Weekly searches over the year, seasonality beneath. Pick a range.

5K3KSpike '24Spike '25Black Friday '25SepDecMarJunAugNovMarMay

No pronounced peak months · busiest ÷ quietest = 2.0×

Search terms

Top Glycine search terms shoppers use

The exact words shoppers type, with yearly volume, growth, and conversion.

  • glycine164K/yr
  • glycine supplement11K/yr
  • l-glycine8K/yr
  • l glycine5K/yr
  • glycine 3g7K/yr
  • glycin2K/yr

Reviews and returns

What reviews say buyers love and hate about Glycine

What buyers praise, what they complain about and why they send it back, from the reviews.

Complain

Sleep Quality11%+2.20

not much difference to sleep quality

makes it more difficult to sleep

was too wired for sleep

Dosage8%−0.07

Apart from that some capsules are half empty

I dont even know how to accurately measure the daily dose with mistakes as it stands

NOT 1500 mg

Advertised Vs Actual Product5%−0.04

Utterly deceptive

Vegavero claim in their photo that it is 'MADE IN GERMANY' - that is incorrect

this is no different to my pictured current brand

Side Effects5%−0.03

serious side effects are possible

Side effects

Overdose taking it everyday made me sedated and nauseuous

Quality-Overall4%

Bad quality

it at least seems poorer quality than Bulk

I don't think this is very good quality

Love

Sleep Quality28%+2.20

Helps me sleep

Better sleep

Helps me to sleep well

Quality-Overall11%

Excellent product

Solid, value glycine with a clean profile

I'm happy with the quality

Value For Money9%+0.27

Good value for money

Good deal

the 100 servings offer excellent value for money

Taste-Overall6%+0.19

Tastes nice as well

has no unpleasant taste

The taste is naturally sweet and pleasant

Solubility5%+0.25

Mixes easily

The powder mixes well

This mixes well

Return

0.1% Return rate 0% Fixable by listing

Functionality-Overall50%█▁▁▁▁▁

Doesn't work for everyone

No results

Ease Of Chewing/Swallowing50%█▁▁▁▁▁

FAQ

Common Glycine questions

Answered from the same tracked data.