---
title: "L Theanine 400mg — $11K/mo Amazon US Product Research (2026)"
canonical_url: "https://flapen.com/research/us/health-household/l-theanine-400mg"
last_updated: "2026-08-12T15:07:47.505Z"
locale: en
meta:
description: "Amazon product research for l theanine 400mg: $11K/mo market, demand, competition, pricing, reviews & the verdict. Know if it's worth selling — Flapen."
"og:description": "Amazon product research for l theanine 400mg: $11K/mo market, demand, competition, pricing, reviews & the verdict. Know if it's worth selling — Flapen."
"og:title": "L Theanine 400mg — $11K/mo Amazon US Product Research (2026)"
---
# **L Theanine 400mg**
**Skip it**
A concentrated shelf (top 5 take 100% of clicks) — this niche doesn't clear our bar today.
Market size 30Growth 37Conversion 85Competition 0Returns 100Price range 87Avg price 92Brand share 0Review moat 53Quality gap 24
**Returns**
**Incredible****0.0%**
return rate — above 5% kills the launch gate
**Avg price**
**Great****$52.80**
avg listing price — sweet spot $15–$100
**Price range**
**Great****$18.65–$109.15**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Conversion**
**Great****9.4%**
search→purchase rate — share of searches ending in a sale
**Review moat**
**Good****1,397.2**
avg incumbent reviews — the moat a new listing must climb
**Growth**
**Okay****+9.3%**
90-day search growth — must beat 0% to launch
**Market size**
**Okay****$133K**
$133K/yr · 27K searches
**Quality gap**
**Bad****4.6★**
avg incumbent rating — lower means beatable quality
**Competition**
**Bad****100%**
top-5 click share — a locked-up shelf
**Brand share**
**Bad****100%**
top-5 brand share — brand-locked demand
**Signals**[** High Price**](https://flapen.com/research/niches?market=us&signal=high_price "Avg price > $50")
## **Is l theanine 400mg profitable on Amazon?**
According to Flapen's Amazon United States niche tracking, l theanine 400mg is a $133K/yr Amazon United States market (27K searches/yr). The top 5 brands hold 100% of demand. Demand peaks in Jul–Aug. Verdict: Skip it — 42/100.
Data updated Jul 25, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **l theanine 400mg market size & sales**
Units sold, revenue, conversion and listing quality across the tracked shelf.
- **Units sold / yr**
- **3K–3K**
- avg 500–750/product
- **Revenue / yr**
- **$132K–$158K**
- units × avg price
- **Conversion rate**
- **9.4%**
- **Avg BSR**
- **#40**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **100%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **97 months**
- **Avg seller age**
- **164 days**
## **Competition: brands, sellers & click share**
The top 5 products capture 100% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**3 **▼falling
**Sellers**
**4**
**Top-5 brand share**
**100%**
Top 20: 100%
**Top-5 click share**
**100%**
Top 20: 100%
**Open market**
**0%**
- Pure Encapsulations92% - NUTRAHARMONY5% - Integrative Therapeutics4% - Open — no brand owns it (0%)
## **l theanine 400mg demand & seasonality**
Weekly Amazon search volume, last 104 weeks — +9.3% search growth over the last 90 days.
3K2KSpike '24Spike '25Prime Day '25Holiday '25Spike '26 seasonSepDecMarJunAugNovMarMay
Peak months: Jul, Aug · busiest ÷ quietest = 4.0×
[**Open Trend **](https://flapen.com/research/us/health-household/l-theanine-400mg/trend)
## **Top l theanine 400mg search terms shoppers use**
The exact queries shoppers type, with yearly volume, growth and conversion.
- **pure encapsulations l-theanine**12K/yr+7.6%10.8% conv. - **pure l theanine**9K/yr+5.0%8.8% conv. - **l theanine pure encapsulations**5K/yr+20.9%9.8% conv. [**All search terms **](https://flapen.com/research/us/health-household/l-theanine-400mg/search-terms)
## **Top l theanine 400mg products & what they sell for**
Every tracked product — its share of the shelf, its review moat, and what it sells for.
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%20%$27K40%$53K60%$80K80%$106K1001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 5 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Pure Encapsulations L-Theanine - Amino Acid Supplement to Support Relaxation Stress & Nervous System* - 60 Capsules**Pure Encapsulations**$62.42**4.7★915 rev](https://www.amazon.com/dp/B0016CXZJO) [2**Pure Encapsulations L-Theanine - Amino Acid Supplement to Support Relaxation Stress & Nervous System* - 120 Capsules**Pure Encapsulations**$109.15**4.7★915 rev](https://www.amazon.com/dp/B0016CXYK4) [3**Pure Encapsulations Cortisol Calm - Supports Cortisol Health & Relaxation* - Contains Ashwagandha & L-Theanine - Restful Sleep - 60 Capsules**Pure Encapsulations**$52.73**4.5★1,383 rev](https://www.amazon.com/dp/B003PR2ZD0) [4**L Theanine 400 mg | L-Theanine Stress Relief | Extra Strength Supplement | Lab Tested | Relaxation Sleep & Calm Support | For Men & Women | Plant Based Non-GMO & Gluten-Free | 120 Vegan Capsules**NUTRAHARMONY**$18.65**4.6★2,155 rev](https://www.amazon.com/dp/B0C9N1Q5QS) [5**Integrative Therapeutics L-Theanine - Amino Acid Supplement for Stress & Relaxation Support* - Vegan Gluten-Free & Dairy-Free - Third-Party Tested - 60 Capsules (30 Servings)**Integrative Therapeutics**$21.06**4.6★1,618 rev](https://www.amazon.com/dp/B0036H0CV6)
### **Newest**
by launch date
[**L Theanine 400 mg | L-Theanine Stress Relief | Extra Strength Supplement | Lab Tested | Relaxation Sleep & Calm Support | For Men & Women | Plant Based Non-GMO & Gluten-Free | 120 Vegan Capsules**NUTRAHARMONY**$18.65**2,155 rev3y ago](https://www.amazon.com/dp/B0C9N1Q5QS) [**Pure Encapsulations Cortisol Calm - Supports Cortisol Health & Relaxation* - Contains Ashwagandha & L-Theanine - Restful Sleep - 60 Capsules**Pure Encapsulations**$52.73**1,383 rev16y ago](https://www.amazon.com/dp/B003PR2ZD0) [**Pure Encapsulations L-Theanine - Amino Acid Supplement to Support Relaxation Stress & Nervous System* - 60 Capsules**Pure Encapsulations**$62.42**915 rev18y ago](https://www.amazon.com/dp/B0016CXZJO) [**Pure Encapsulations L-Theanine - Amino Acid Supplement to Support Relaxation Stress & Nervous System* - 120 Capsules**Pure Encapsulations**$109.15**915 rev18y ago](https://www.amazon.com/dp/B0016CXYK4) [**Integrative Therapeutics L-Theanine - Amino Acid Supplement for Stress & Relaxation Support* - Vegan Gluten-Free & Dairy-Free - Third-Party Tested - 60 Capsules (30 Servings)**Integrative Therapeutics**$21.06**1,618 rev18y ago](https://www.amazon.com/dp/B0036H0CV6)
### **Trending**
90-day click momentum
[**Pure Encapsulations L-Theanine - Amino Acid Supplement to Support Relaxation Stress & Nervous System* - 60 Capsules**Pure Encapsulations**$62.42**4.7★**▲ 22%**](https://www.amazon.com/dp/B0016CXZJO) [**Pure Encapsulations Cortisol Calm - Supports Cortisol Health & Relaxation* - Contains Ashwagandha & L-Theanine - Restful Sleep - 60 Capsules**Pure Encapsulations**$52.73**4.5★**▲ 12%**](https://www.amazon.com/dp/B003PR2ZD0) [**Integrative Therapeutics L-Theanine - Amino Acid Supplement for Stress & Relaxation Support* - Vegan Gluten-Free & Dairy-Free - Third-Party Tested - 60 Capsules (30 Servings)**Integrative Therapeutics**$21.06**4.6★**▼ 22%**](https://www.amazon.com/dp/B0036H0CV6) [**L Theanine 400 mg | L-Theanine Stress Relief | Extra Strength Supplement | Lab Tested | Relaxation Sleep & Calm Support | For Men & Women | Plant Based Non-GMO & Gluten-Free | 120 Vegan Capsules**NUTRAHARMONY**$18.65**4.6★**▼ 25%**](https://www.amazon.com/dp/B0C9N1Q5QS) [**Pure Encapsulations L-Theanine - Amino Acid Supplement to Support Relaxation Stress & Nervous System* - 120 Capsules**Pure Encapsulations**$109.15**4.7★**▼ 44%**](https://www.amazon.com/dp/B0016CXYK4)
## **What reviews say buyers love and hate about l theanine 400mg**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Sleep Quality**27%
*“Great for sleep”*
**Quality-Overall**16%
*“Excellent product”*
**Stress/Anxiety**12%
*“It really helps with anxiety”*
**Soothing Effect**8%
*“Calming and relaxing”*
**Advertised Vs Actual Product**6%
*“As advertised”*
**Efficiency**5%
*“Works well”*
**Focus Enhancement**3%
*“Focus is up”*
**Dosage**2%
*“Great With Prescription”*
**Fever Relief**2%
*“Helped hot flashes in 3 days”*
**Vitamin**2%
*“Quality supplements”*
### **What buyers complain about **
**Sleep Quality**23%
*“I still dont sleep”*
**Functionality-Overall**21%
*“Cortisol calm did not work for me”*
**Dosage**9%
*“I will say that taking 2+ pills doesnt enhance effects for me, at all”*
**Value For Money**8%
*“Not worth the price”*
**Side Effects**5%
*“I will say that taking 2+ pills doesnt enhance effects for me, at all”*
**Heart Health**3%
*“Severe g. i. issues”*
**Allergies**3%
*“Allergic reaction”*
**Vitamin**3%
*“I never expect much from supplements because nothing ever did much to help”*
**Taste-Overall**3%
*“no taste”*
**Stress/Anxiety**2%
*“taking this supplement as well made me shaky, weak, and sleepy”*
### **Top return reasons **
**Value For Money**25%
**Side Effects**25%
**Sleep Quality**13%
**Compatibility-Overall**13%
**Dosage**13%
**Magnesium**13%
## **Common l theanine 400mg questions**
- **Is l theanine 400mg profitable to sell on Amazon United States?**
- The niche generates $133K/yr across 5 tracked products. 90-day search growth is +9.3%. Flapen's verdict: Skip it (42/100).
- **How competitive is the l theanine 400mg niche?**
- 3 brands and 4 sellers compete. The top 5 products take 100% of clicks and top 5 brands hold 100% of demand.
- **What do buyers complain about in l theanine 400mg?**
- Top complaints mined from reviews: Sleep Quality, Functionality-Overall, Dosage. The return rate is 0.0%.
- **When does demand for l theanine 400mg peak?**
- Demand peaks in Jul–Aug; the busiest month runs 4.0× the quietest.
- **What does it cost to enter the l theanine 400mg niche?**
- Listings span $18.65–$109.15; the average listing price is $52.80 (sweet spot $15–$100). The average incumbent carries 1,397 reviews — the moat a new listing must climb.
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