Which supplement works better to improve cognitive ability: caffeine anhydrous or iron?

Ratings at a Glance

Supplement	Effectiveness Rating	Confidence Rating
Caffeine Anhydrous
Iron

Effectiveness Rating: Caffeine Anhydrous vs Iron

The effectiveness rating is a measure of the supplements' ability to improve cognitive ability. This rating answers the question of whether or not a supplement does what it claims. The evidence backing up iron is great, while the evidence backing up caffeine anhydrous is good. Iron should be able to improve cognitive ability more effectively, however both supplements should provide positive results.

Confidence Rating: Caffeine Anhydrous vs Iron

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.

Caffeine Anhydrous's confidence rating is higher than iron's. This means caffeine anhydrous's effectiveness rating from above is more valid. This does not necessarily mean that caffeine anhydrous works better, it simply means the evidence (included in this database) backing up caffeine anhydrous is more established.