Life Extension D,L-Phenylalanine 500 mg

Life Extension · Capsule · 500 mg

Price/day

€0.17

Dose

500 mg

Servings/pack

100

Pack price

€16.90

Transparency Index

7.8/10

Acceptable Interesting dopamine precursor with possible pain modulation, though evidence for the D-form is dated.

Rating breakdown

Evidence for ingredient 5.0/10

L-phenylalanine as a neurotransmitter precursor has moderate evidence. The D-form is thought to inhibit enkephalinase (pain modulation), but the studies are old.

Value for money 8.0/10

€0.17 per day for Life Extension quality is very affordable.

Product quality 8.0/10

Life Extension standard quality; 50/50 D/L mixture, pure amino acid.

Label honesty 9.0/10

D,L-form and quantity clearly declared.

Third-party testing 8.0/10

Life Extension has its own analytical lab; COAs available.

Product Description

The D,L-form combines both isomers: L-phenylalanine is converted to L-tyrosine → dopamine → noradrenaline. D-phenylalanine is thought to inhibit enkephalinase, prolonging endogenous endorphins (natural pain modulation).

What We Like

Dual mechanism: neurotransmitter precursor + pain modulation
100 capsules = 3+ months supply
Life Extension quality standard
Very low price

What We’re Missing

Studies on the D-form are mostly from the 1980s
Not suitable for people with PKU (phenylketonuria)
Do not combine with MAO inhibitors or levodopa

Usage Recommendation

1 capsule 1–2× daily on an empty stomach. Avoid in the evening — stimulating via the dopamine pathway.

Other D,L-Phenylalanine products

Pure Encapsulations DL-Phenylalanine 500mg

7.7/10

Recommended

Ingredient dossier

DLPA combines the neurotransmitter precursor L-phenylalanine with the D-form, which may prolong endogenous endorphins. Moderate evidence, older study base.

Read full dossier: D,L-Phenylalanine →