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L-arginine supplements

L-arginine 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: 0.15 g/kg. 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.

Powders (4)

ProductOne servingOne serving vs research doseTo reach the research doseLabel's daily maximumProof
NOW Sports L-Arginine Powder · label 20 Jun 20246 gBelow research dose2 servings reach 11.25 g at 75 kg (more than directed)6 g (1 serving)Label claim only
Nutricost L-Arginine Powder · label 20 Jun 20245 g in 1 scoop (5 g)Below research dose3 servings reach 11.25 g at 75 kg (more than directed)5 g (1 serving)Label claim only
Doctor's Best Pure L-Arginine Powder · label 28 May 20194.96 g in 1 scoop (6 g)Below research dose3 servings reach 11.25 g at 75 kg (more than directed)4.96 g (1 serving)Label claim only
NutraBio L-Arginine · label 21 May 20251.5 g in 1 scoop (1.5 g)Below research dose8 servings reach 11.25 g at 75 kg (more than directed)4.5 g (3 servings)Label claim only

Capsules (8)

ProductOne servingOne serving vs research doseTo reach the research doseLabel's daily maximumProof
Pure Encapsulations L-Arginine · label 23 Aug 20231.16 g in 2 capsulesBelow research dose20 capsules reach 11.25 g at 75 kg (more than directed)3.47 g (6 capsules)Label claim only
Puritan's Pride L-Arginine 1000 mg · label 25 Sep 20241 g in 1 capsuleBelow research dose12 capsules reach 11.25 g at 75 kg (more than directed)6 g (6 capsules)Label claim only
Thorne L-Arginine · label 22 Aug 20251 g in 2 capsulesBelow research dose23 capsules reach 11.25 g at 75 kg (more than directed)2 g (4 capsules)Label claim only
Havasu Nutrition L-Arginine Capsules + L-Citrulline · label 11 Oct 2026827 mg in 2 capsulesBelow research dose28 capsules reach 11.25 g at 75 kg (more than directed)827 mg (2 capsules)Label claim only
NOW L-Arginine 700 mg · label 23 Jun 2021700 mg in 1 capsuleBelow research dose17 capsules reach 11.25 g at 75 kg (more than directed)700 mg (1 capsule)Label claim only
Nutricost L-Arginine + L-Citrulline 750 mg · label 25 Jul 2024500 mg in 1 capsuleBelow research dose23 capsules reach 11.25 g at 75 kg (more than directed)500 mg (1 capsule)Label claim only
Nutricost L-Arginine 500 mg · label 24 Jan 2024500 mg in 1 capsuleBelow research dose23 capsules reach 11.25 g at 75 kg (more than directed)500 mg (1 capsule)Label claim only
Swanson L-Arginine 500 mg · label 22 Aug 2025500 mg in 1 capsuleBelow research dose23 capsules reach 11.25 g at 75 kg (more than directed)1 g (2 capsules)Label claim only

Tablets (5)

ProductOne servingOne serving vs research doseTo reach the research doseLabel's daily maximumProof
Micro Ingredients L-Arginine · label 19 Nov 20211.5 g in 2 tabletsBelow research dose15 tablets reach 11.25 g at 75 kg (more than directed)1.5 g (2 tablets)Label claim only
Best Naturals L-Arginine 1000 mg · label 16 Jun 2022827 mg in 1 tabletBelow research dose14 tablets reach 11.25 g at 75 kg (more than directed)2.48 g (3 tablets)Label claim only
Jarrow Formulas Arginine 1000 mg · label 22 Feb 2024827 mg in 1 tabletBelow research dose14 tablets reach 11.25 g at 75 kg (more than directed)1.65 g (2 tablets)Label claim only
Nature's Bounty L-Arginine 1000 mg · label 24 Jun 2016827 mg in 1 tabletBelow research dose14 tablets reach 11.25 g at 75 kg (more than directed)2.48 g (3 tablets)Label claim only
Source Naturals L-Arginine 1,000 mg · label 25 Sep 2023827 mg in 1 tabletBelow research dose14 tablets reach 11.25 g at 75 kg (more than directed)2.48 g (3 tablets)Label claim only

17 products. The verdict judges one serving, as the label gives it. Read the l-arginine 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.