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Winter Wellness

product on market Capsule Life Extension Safety: 100/100
100/100

This product looks safe

  • No ingredients exceed tolerable upper intake levels
  • 50% of ingredients have research evidence
A Label Compliance Grade

What the Evidence Says

AI-generated · Qwen 3.6 · methodology

L-cysteine serves as a precursor to glutathione to support antioxidant defenses, while L-theanine is associated with relaxation and stress reduction. Research evidence for these specific applications is generally moderate. The overall evidence coverage for this specific formulation is limited.

AI-generated summary based on research evidence. Not medical advice.

Label

Product Label

Label for Winter Wellness
Open Full PDF View on NIH DSLD →
Details

Label Data

2 Capsule(s)
Serving Size
30
Servings
Other Combinations
Product Type
50%
Evidence Coverage
Ingredients

Supplement Facts — Evidence Check

L-Cysteine
700 mg
280 mg
Market median: 200.0mg (358 products) 9 studies (A:0, B:2)

Other Ingredients

Vegetable Cellulose Dicalcium Phosphate Microcrystalline Cellulose Silica Vegetable Stearate
Claims

Label Claims — Verification

Unverified All Other
Unverified Structure/Function
Info

Product Information

Directions for Use

Read the entire label and follow the directions carefully prior to use. DIRECTIONS: Take two (2) capsules daily with or without food, or as recommended by a healthcare practitioner.

Warnings & Precautions

WARNINGS: ~ KEEP OUT OF REACH OF CHILDREN.

~ DO NOT EXCEED RECOMMENDED DOSE. ~ Do not purchase if outer seal is broken or damaged.

~ When using nutritional supplements, please consult with your physician if you are undergoing treatment for a medical condition or if you are pregnant or lactating.

Additional Information

Scan for product info

Store tightly closed in a cool, dry place.

Enhances and Balances Immune Response*

To report a serious adverse event or obtain product information, contact 1-866-280-2852.

Q01739B

Metadata

Product Details

UPC / SKU7 37870 17396 0
DSLD Entry Date2016-04-22
Product TypeOther Combinations
FormCapsule
DSLD ID59062
Data Updated2026-04-11
Research

Research Evidence

37
Research Sources
53
Avg Quality
22
Rct
10
Systematic Review
3
Meta Analysis
1
Clinical Trial
1
Openfda Safety
B Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials
Systematic Review Nutritional neuroscience 2026 PubMed DOI
B The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis
Meta Analysis Sleep medicine reviews 2025 PubMed DOI
B The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness
Rct Nutritional neuroscience 2010 PubMed DOI
B Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial
Rct Nutrients 2019 PubMed DOI
B The Role of Supplements and Over-the-Counter Products to Improve Sleep in Children: A Systematic Review
Systematic Review International journal of molecular sciences 2023 PubMed DOI
B Effects of Tea (Camellia sinensis) or its Bioactive Compounds l-Theanine or l-Theanine plus Caffeine on Cognition, Sleep, and Mood in Healthy Participants: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Meta Analysis Nutrition reviews 2025 PubMed DOI
B Effect of Alpha-S1-Casein Tryptic Hydrolysate and L-Theanine on Poor Sleep Quality: A Double Blind, Randomized Placebo-Controlled Crossover Trial
Rct Nutrients 2022 PubMed DOI
B Effect of L-theanine on selective attention in a traffic-related reaction task in sleep-deprived young adults: a double-blind placebo-controlled, crossover study
Rct Nutritional neuroscience 2025 PubMed DOI
B The combined effects of L-theanine and caffeine on cognitive performance and mood
Rct Nutritional neuroscience 2008 PubMed DOI
B Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis
Meta Analysis Nutrition reviews 2014 PubMed DOI
View all evidence for L Theanine →
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This product page is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before taking any supplement.