l carnitine vs l theanine Natural Rhythm CoQ10-ZEN | Coenzyme Q10 (100 mg) + L-Carnitine (125 mg) + L-Theanine (150 mg) | Dietary Supplement Capsules | Cellular Energy & Daily Wellness Support Can L-Theanine Clear Brain Fog

see also Cryan et al., 2019 for a review, and in addition A meta-analysis across several studies involving humans failed to find any benefit of probiotics on cognition (Marx et al., 2020)

For visible before-and-after changes in overall skin tone, most people follow a starter course of 6 to 10 sessions spaced 5 to 7 days apart, followed by maintenance sessions to preserve the results

GHK-Cu 1mg 2x weekly rather than daily (saves 65%), Cerebrolysin 10mL sessions quarterly rather than monthly (saves 66%)

Puto, L

The guarantee isnt quite as long as something like Swansons 100-day promise, but it should still be enough for you to get a sense of whether the product works for you