Mostly, my first aid capacities are carried between my ears.
But physical stuff?
A dozen each of:
– Tylenol (acetaminophen)
– Advil (ibuprofen)
About 6 each of:
– Aspirin (anti-coagulant)
– Benadryl (topically for insect bites, poison oak; orally for hay fever, cold symptoms, motion sickness, and insomnia. Normally injected for severe allergic reactions, I’d have someone snort it to deliver it ASAP.)
– a few packets of fiber for when things aren’t moving.
– Imodium (loperamide) when they’re moving too fast.
I change it a bit seasonally and climatically.
California foothills: more posion-oak treatment (steroid creams, maybe some prednisone pills).
Tropics or a really wet trip: anti-fungal cream for between one’s toes.
Desert trip: great tweezers.
Solo trip: small mirror to inspect oneself (or smart phone).
A few sizes of bandaids (reattached my fingertip with one on a NZ trip).
Luekotape on a non-stick backing.
2-3 single-servings (0.5-gram) triple-antibiotic ointment (mostly to keep cuts hydrated so the edges can knit back together rather than drying out).
Victorinox Classic (which might be in another organizer bag) for the scissors, blade, and (yeah, minimal) tweezers.
A few needles enbedded in a small bit of waxed cardboard (protects the sharp end and doubles as a fire starter).