Check a label

L-theanine supplements

L-theanine is taken as one dose before training, so what matters is how much one serving gives. We compare each product's serving with what studies use: 100–200 mg. Products whose serving reaches that come first, then by how close one serving gets (counted only up to the top of the range); commission never changes the order.

Chews (1)

ProductOne servingOne serving vs research doseTo reach the research doseLabel's daily maximumProof
Nature Made L-Theanine 200 mg Chewable · label 25 Jul 2024200 mg in 1 chewEffective doseOne serving200 mg (1 chew)Label claim only

Capsules (12)

ProductOne servingOne serving vs research doseTo reach the research doseLabel's daily maximumProof
Double Wood L-Theanine 200 mg · label 22 Jan 2021200 mg in 1 capsuleEffective doseOne serving400 mg (2 capsules)Label claim only
Jarrow Formulas Theanine 200 mg · label 24 Jan 2024200 mg in 1 capsuleEffective doseOne serving200 mg (1 capsule)Label claim only
Momentous L-Theanine · label 23 Feb 2025200 mg in 1 capsuleEffective doseOne serving200 mg (1 capsule)NSF Certified for Sport
Nootropics Depot L-Theanine 200 mg Capsules · label 21 Feb 2023200 mg in 1 capsuleEffective doseOne serving200 mg (1 capsule)Label claim only
NOW L-Theanine 200 mg · label 25 Jul 2024200 mg in 1 capsuleEffective doseOne serving400 mg (2 capsules)Label claim only
NutraBio L-Theanine · label 23 May 2024200 mg in 1 capsuleEffective doseOne serving600 mg (3 capsules)Label claim only
Nutricost L-Theanine 200 mg · label 21 Jul 2022200 mg in 1 capsuleEffective doseOne serving400 mg (2 capsules)Label claim only
Pure Encapsulations L-Theanine · label 23 Aug 2023400 mg in 2 capsulesEffective doseOne serving1.2 g (6 capsules)Label claim only
Sports Research L-Theanine 200 mg · label 23 Feb 2025200 mg in 1 capsuleEffective doseOne serving200 mg (1 capsule)Label claim only
Thorne Theanine · label 25 Sep 2025200 mg in 1 capsuleEffective doseOne serving600 mg (3 capsules)Label claim only
Doctor's Best L-Theanine 150 mg · label 16 Jun 2022150 mg in 1 capsuleEffective doseOne serving150 mg (1 capsule)Label claim only
Swanson Suntheanine L-Theanine 100 mg · label 21 Dec 2024100 mg in 1 capsuleEffective doseOne serving200 mg (2 capsules)Label claim only

13 products. The verdict judges one serving, as the label gives it. Read the l-theanine guide for the studies behind the dose. "Proof" is a published independent lab test, a certifier listing we read on the certifier's own site (usually for listed lots only), or "Label claim only" when we found neither.