For coffee and tea drinkers
Caffeine + L-theanine
A common pair, often in a 1:2 ratio – also sold together in one capsule.
4.6¢a day
at the lowest prices, quality 75+
$0.48with typical prices
$1.41
a month
$17
a year, at the lowest prices
What it’s for
Caffeine makes you feel more alert. L-theanine from tea leaves is taken to feel calm but alert, and the pair is often taken for focus – studies are small.
Not medical advice.
What’s in it
Caffeine
100 mg caffeine There’s no recommended amount a day. For healthy adults, 400 mg a day is cited as an amount not generally linked to negative effects (FDA).Not a recommendation. Not medical advice.
- Lowest
- 3.6¢
- Typical
- 7.9¢
L-theanine
200 mg L-theanine There’s no official daily amount for L-theanine.Not a recommendation. Not medical advice.
- Lowest
- 1.1¢
- Typical
- $0.40
Each color is one part of the combo – per day.
| Part | Lowest | Typical |
|---|---|---|
| Caffeine | 3.6¢ | 7.9¢ |
| L-theanine | 1.1¢ | $0.40 |
Not medical advice
We compare prices and label data. The amounts are the ones we compare by – usually the common amount on labels – not recommendations. Talk to a doctor or pharmacist before taking supplements, especially if you are under 18, pregnant or on medication.
Prices: our own check of 7,383 products in US online stores (Nov 1, 2026). How we check
