Which supplement works better to improve running performance: beta alanine or tryptophan?

Ratings at a Glance

Supplement	Effectiveness Rating	Confidence Rating
Beta Alanine
Tryptophan

Effectiveness Rating: Beta Alanine vs Tryptophan

The effectiveness rating is a measure of the supplements' ability to improve running performance. This rating answers the question of whether or not a supplement does what it claims. Both beta alanine and tryptophan have good (but not great) evidence showing they may be able to improve running performance. Both supplements should provide some positive results.

Confidence Rating: Beta Alanine vs Tryptophan

Another factor to take into account when comparing supplements is the confidence rating. This rating is a measure of how valid each supplement's effectiveness rating is. Remember, the confidence rating is a measure of how much you can trust the effectiveness rating. This rating is based on how many studies are included in the database on a supplement's claims. Ideally, you want a high effectiveness AND confidence rating.

Beta Alanine's confidence rating is higher than tryptophan's. This means beta alanine's effectiveness rating from above is more valid. This does not necessarily mean that beta alanine works better, it simply means the evidence (included in this database) backing up beta alanine is more established.