How long should I try hair loss care before assessing a change?

First establish reasonable expectations: Hair growth is measured in months, and improvement of scalp condition generally requires weeks to months of observation. Any statement of "immediate results" is not consistent with hair biology.

The correct way to observe the effect is to regularly check and compare, rather than relying only on subjective impressions: compare fixed indicators (scalp status, hair density changes) before and after, and the records can be viewed. The effect varies from person to person. If the progress is not obvious, you should communicate truthfully instead of continuing to add services. If hair loss itself requires treatment, dermatology protocols should prevail (Grover 2013, PMID 23974577).