Yes if they are not undergoing active treatment and if there is a clear indication such as post-surgical recovery, radiotherapy-related tissue repair, or immune support
Requires indefinite use
While not all nootropics are safe or effective, there are a number that are, especially: adaptogen herbs medicinal and adaptogenic mushrooms bacopa ginseng DHA/fish oil ginkgo biloba Other types that can help improve memory, thinking speed and attention span are green coffee extract or matcha green tea, along with caffeine and L-theanine
Consort 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trial
The search terms for the first were 'glutathione AND skin lightening', and for the second 'glutathione AND randomised controlled trial'
This pathway can absorb approximately 1.52 micrograms per meal , making it efficient for dietary B12 but limited for high-dose supplementation