Performance
Caffeine (Camellia sinensis leaf)
Also known as: green tea extract, EGCG-containing caffeine, theine
Caffeine from Camellia sinensis (green tea) is a central nervous system stimulant that enhances alertness, focus, and endurance. This source also provides catechin antioxidants including EGCG.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every Caffeine (Camellia sinensis leaf) product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Nutricost Caffeine + L-Theanine Capsules | 97 A | $0.53 |
| 2 | Nutricost Caffeine Capsules | 92 A | $0.12 |
| 3 | Thorne Green Tea Phytosome | 92 A | $0.57 |
| 4 | Transparent Labs Fat Burner | 92 A | $0.92 |
| 5 | NOW Foods L-Theanine | 91 A | $0.16 |
| 6 | Transparent Labs BULK Pre-Workout | 90 A | $1.67 |
| 7 | Pure Encapsulations CurcumaSorb Mind | 90 A | $2.57 |
| 8 | Pure Encapsulations Green Tea extract (decaffeinated) | 90 A | $0.52 |
| 9 | Thorne Memoractiv™ | 89 A | $2.33 |
| 10 | Nutricost Pre-Workout For Women Powder | 89 A | $0.73 |
| 11 | Zhou Nutrition Energy + Focus | 89 A | $0.35 |
| 12 | Nutricost Pre-Workout Complex | 89 A | $0.83 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much Caffeine (Camellia sinensis leaf) should I take?
The typical range is 50–200 mg caffeine daily for cognitive effects; up to 400 mg daily is generally safe for most adults. tolerance develops; cycling recommended to maintain efficacy; effects typically last 3–5 hours
When should I take Caffeine (Camellia sinensis leaf)?
morning or early afternoon to avoid sleep disruption. either, though food may delay absorption.
Which form of Caffeine (Camellia sinensis leaf) is best?
green tea leaf extract. Other forms in the catalog: dried leaf powder.
Is Caffeine (Camellia sinensis leaf) safe?
Commonly reported: jitteriness, anxiety, insomnia, elevated heart rate at high doses.
Which Caffeine (Camellia sinensis leaf) supplement scores highest?
Nutricost Caffeine + L-Theanine Capsules, at 97/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- energy and alertness
- mental focus
- physical performance
- endurance
How it works
- adenosine receptor antagonism
- increases dopamine and norepinephrine
- enhances sympathetic nervous system activity
Dosage
- Typical range
- 50–200 mg caffeine daily for cognitive effects; up to 400 mg daily is generally safe for most adults
- Timing
- morning or early afternoon to avoid sleep disruption
- With food
- either, though food may delay absorption
- Duration
- tolerance develops; cycling recommended to maintain efficacy; effects typically last 3–5 hours
- Special populations
- pregnant women limit to <200 mg/day; sensitive individuals or anxiety disorders use lower doses or avoid
Forms
- green tea leaf extract· 70/100
- dried leaf powder· 70/100
Safety
Common side effects
- jitteriness
- anxiety
- insomnia
- elevated heart rate at high doses
Contraindications
- uncontrolled hypertension
- cardiac arrhythmias
- severe anxiety disorders
- pregnancy (limit to <200 mg/day)
Products containing Caffeine (Camellia sinensis leaf)
Top-scoring supplements in our catalog that list Caffeine (Camellia sinensis leaf) on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Extensive RCT evidence confirms caffeine's efficacy for cognitive performance, alertness, and endurance across numerous studies. Green tea source provides additional polyphenol benefits.
Grade A: Multiple well-designed human trials support the main claims.
Related in Performance
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.