---
title: "L Theanine — £742K/yr Amazon UK Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/uk/health-personal-care/l-theanine"
last_updated: "2026-07-31T19:39:32.024Z"
locale: en
meta:
description: "Niche score 53/100 · £742K/yr market · 580K searches/yr. Prices mostly outside the sweet spot ($4.98–$17.18) keeps it on the watch list. Data updated Jul 2026."
"og:description": "Niche score 53/100 · £742K/yr market · 580K searches/yr. Prices mostly outside the sweet spot ($4.98–$17.18) keeps it on the watch list. Data updated Jul 2026."
"og:title": "L Theanine — £742K/yr Amazon UK Niche (2026) - Flapen"
---
# **l theanine**
**Worth a look**
Shows low returns (0.0%), but prices mostly outside the sweet spot ($4.98–$17.18) keeps it on the watch list.
Market size 70Growth 27Conversion 97Competition 22Returns 100Price range 18Avg price 24Brand share 53Review moat 50Quality gap 57
**Returns**
**Incredible****0.0%**
return rate — above 5% kills the launch gate
**Conversion**
**Incredible****14.8%**
search→purchase rate — share of searches ending in a sale
**Market size**
**Good****£742K**
£742K/yr · 580K searches
**Quality gap**
**Good****4.4★**
avg incumbent rating — lower means beatable quality
**Brand share**
**Good****73%**
top-5 brand share — brands hold most of the demand
**Review moat**
**Okay****1,515.67**
avg incumbent reviews — the moat a new listing must climb
**Growth**
**Okay****+1.8%**
90-day search growth — must beat 0% to launch
**Avg price**
**Bad****£8.63**
avg listing price — sweet spot $15–$100
**Competition**
**Bad****73%**
top-5 click share — a locked-up shelf
**Price range**
**Bad****£4.98–£17.18**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Signals**[** Low Review Barrier**](https://flapen.com/research/niches?market=uk&signal=low_review_barrier "Top brand's reviews < 500")
According to Flapen's Amazon United Kingdom niche tracking, l theanine is a £742K/yr Amazon United Kingdom market (580K searches/yr). The top 5 brands hold 73% of demand. Demand peaks in Apr–May. Verdict: Worth a look — 53/100.
Data updated Jul 25, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **l theanine market data**
- **Units sold / yr**
- **60K–80K**
- avg 5,000–6,000/product
- **Revenue / yr**
- **£518K–£690K**
- units × avg price
- **Conversion rate**
- **14.8%**
- **Avg BSR**
- **#120**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **93%**
- **Out of stock**
- **10.3%**
- **Avg brand age**
- **36 months**
- **Avg seller age**
- **168 days**
## **Competition & brand share**
The top 5 products capture 73% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**14 **▼falling
**Sellers**
**18**
**Top-5 brand share**
**73%**
Top 20: 100%
**Top-5 click share**
**73%**
Top 20: 100%
**Open market**
**18%**
- NUTRINATION22% - NEW LEAF PRODUCTS21% - Nutrivo12% - Nutricost10% - SS Sport Supplies9% - WeightWorld8%
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — +1.8% search growth over the last 90 days.
13K8KSpike '24Spike '25Spike '26 seasonSepDecMarJunAugNovMarMay
Peak months: Apr, May · busiest ÷ quietest = 2.0×
[**Open Trend **](https://flapen.com/research/uk/health-personal-care/l-theanine/trend)
## **Top l theanine search terms**
- **l theanine**265K/yr+10.7%12.5% conv. - **l-theanine**169K/yr-6.2%12.0% conv. - **l theanine 400mg**22K/yr+108.3%17.0% conv. - **ltheanine**25K/yr+17.8%12.4% conv. - **theanine**26K/yr-3.4%11.5% conv. - **l-theanine 400mg**10K/yr+9.6%15.4% conv. - **suntheanine**7K/yr+4.9%2.4% conv. - **l theanine supplement**34K/yr-80.2%9.6% conv. - **l theanine 100mg**5K/yr-2.1%3.0% conv. - **l- theanine**5K/yr-15.9%7.2% conv. [**All search terms **](https://flapen.com/research/uk/health-personal-care/l-theanine/search-terms)
## **Top l theanine 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.
0%10%£74K20%£148K30%£223K40%£297K101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
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
[1**L Theanine 400mg Capsules - 99.6% Pure L-Theanine | 5 Months Supply - 150 Capsules | Supports Relaxation & Focus Promotes Calm | Zero Additives Vegan & Non-GMO | GMP - Certified Lab Tested**NUTRINATION**£9.48**4.6★171 rev](https://www.amazon.co.uk/dp/B0DJM84N9K) [2**L Theanine Enriched with Vitamin B6 - High Strength L-Theanine Capsules 400mg Natural Nootropics from Green Tea - 120 Vegan Capsules - Made in The UK Supplements by New Leaf**NEW LEAF PRODUCTS**£7.99**4.5★729 rev](https://www.amazon.co.uk/dp/B0CXF33DB8) [3**L Theanine 400mg | 120 Vegan Capsules - 4 Months Supply | Good Alternative to L-Theanine Powder Gummies and Drops | UK Made LTheanine Supplement**Nutrivo**£7.73**4.6★473 rev](https://www.amazon.co.uk/dp/B0CVR1J7NY) [4**Nutricost L-Theanine 200mg 120 Capsules - Non-GMO Gluten Free**Nutricost**£6.66**4.4★9,555 rev](https://www.amazon.co.uk/dp/B01B3RWQNM) [5**L-Theanine Green Tea Extract with Added Lemon Balm Extract and Chelated Magnesium Glycinate - Derived from Green Tea Leaves - Sleep & Relaxation Support - Mental Clarity**SS Sport Supplies**£5.53**4.0★46 rev](https://www.amazon.co.uk/dp/B0GJV27PV3)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**L-Theanine Green Tea Extract with Added Lemon Balm Extract and Chelated Magnesium Glycinate - Derived from Green Tea Leaves - Sleep & Relaxation Support - Mental Clarity**SS Sport Supplies**£5.53**46 rev6mo ago](https://www.amazon.co.uk/dp/B0GJV27PV3) [**L Theanine Gummies - 200 mg L-Theanine Supplement with Lemon Balm & Vitamin B6 - Supports Nervous System & Hormonal Function - Vegan Halal - 60 Count - Novomins**novomins**£11.47**35 rev6mo ago](https://www.amazon.co.uk/dp/B0FZW7882R) [**Natures Best L Theanine 200mg 60 Capsules (2 Month Supply)**NATURE'S BEST**£10.71**49 rev9mo ago](https://www.amazon.co.uk/dp/B0FVGC5GX4) [**L-Theanine 400mg with BioPerine | 120 Vegan Capsules | High Absorption & Bioavailablity L Theanine | Enhanced Sleep at Night | Boost Focus & Relieve Stress | 4 Months Supply | UK Made | by NutriVolv**NutriVolv**£5.73**59 rev10mo ago](https://www.amazon.co.uk/dp/B0FS29C8H3) [**L Theanine 400mg Capsules - 99.6% Pure L-Theanine | 5 Months Supply - 150 Capsules | Supports Relaxation & Focus Promotes Calm | Zero Additives Vegan & Non-GMO | GMP - Certified Lab Tested**NUTRINATION**£9.48**171 rev1y ago](https://www.amazon.co.uk/dp/B0DJM84N9K)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**L Theanine Gummies - 200 mg L-Theanine Supplement with Lemon Balm & Vitamin B6 - Supports Nervous System & Hormonal Function - Vegan Halal - 60 Count - Novomins**novomins**£11.47**4.4★**▲ 235%**](https://www.amazon.co.uk/dp/B0FZW7882R) [**L-Theanine Green Tea Extract with Added Lemon Balm Extract and Chelated Magnesium Glycinate - Derived from Green Tea Leaves - Sleep & Relaxation Support - Mental Clarity**SS Sport Supplies**£5.53**4.0★**▲ 170%**](https://www.amazon.co.uk/dp/B0GJV27PV3) [**Natures Best L Theanine 200mg 60 Capsules (2 Month Supply)**NATURE'S BEST**£10.71**4.7★**▲ 129%**](https://www.amazon.co.uk/dp/B0FVGC5GX4) [**L Theanine 400mg Capsules - 99.6% Pure L-Theanine | 5 Months Supply - 150 Capsules | Supports Relaxation & Focus Promotes Calm | Zero Additives Vegan & Non-GMO | GMP - Certified Lab Tested**NUTRINATION**£9.48**4.6★**▲ 65%**](https://www.amazon.co.uk/dp/B0DJM84N9K) [**Ashwagandha KSM 66 Complex 3000mg Enhanced with L-Tryptophan & Vitamin B6 (2 Month Supply) Ashwagandha High Strength Capsules with 250mg Extract (Not Gummies or Powder) - Vegan UK Made**Nutrition Geeks**£7.26**4.4★**▲ 60%**](https://www.amazon.co.uk/dp/B0C111HFF4)
**~~View all trending →~~**
## **What buyers say about l theanine**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Sleep Quality**15%
*“Helpful for sleep”*
**Quality-Overall**11%
*“appears to be well made”*
**Stress/Anxiety**9%
*“Great for anxiety”*
**Value For Money**9%
*“Good value for money”*
**Focus Enhancement**5%
*“less brain fog”*
**Ease Of Chewing/Swallowing**4%
*“I found the chewy”*
**Vitamin**4%
*“Good supplement”*
**Soothing Effect**4%
*“Very calming”*
**Ease Of Use**3%
*“Ease of use”*
**Advertised Vs Actual Product**3%
*“As advertised”*
### **What buyers complain about **
**Dosage**9%
*“Not enough to be clinically effective at all”*
**Sleep Quality**8%
*“Didn't help with Sleep”*
**Smell**8%
*“Smelled absolutely awful”*
**Ingredients-Overall**6%
*“Ingredients have changed”*
**Side Effects**5%
*“After taking these for a few day I was experiencing really bad pain in my abdomen”*
**Functionality-Overall**5%
*“Dont work”*
**Advertised Vs Actual Product**5%
*“misleading”*
**Stress/Anxiety**5%
*“Stress and anexity”*
**Quality-Overall**3%
*“Just wish the quality control was a bit better”*
**Vitamin**2%
*“Think the vit B6 levels is low for a supplement”*
### **Top return reasons **
**Certifications**100%
## **Common questions**
- **Is l theanine profitable to sell on Amazon United Kingdom?**
- The niche generates £742K/yr across 15 tracked products. 2 of 4 products launched in the last 360 days are still selling. 90-day search growth is +1.8%. Flapen's verdict: Worth a look (53/100).
- **How competitive is the l theanine niche?**
- 14 brands and 18 sellers compete. The top 5 products take 73% of clicks and top 5 brands hold 73% of demand.
- **What do buyers complain about in l theanine?**
- Top complaints mined from reviews: Dosage, Sleep Quality, Smell. The return rate is 0.0%.
- **When does demand for l theanine peak?**
- Demand peaks in Apr–May; the busiest month runs 2.0× the quietest.
- **What does it cost to enter the l theanine niche?**
- Listings span £4.98–£17.18; the average listing price is £8.63 (sweet spot $15–$100). The average incumbent carries 1,516 reviews — the moat a new listing must climb.
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