At face value, personal medication coming into the USA should be treated the same by US customs (i.e. no differently) as for something coming from China or India? So based on your previous reports, there should be no problem entering the US?
So I guess you're really asking how the package should be marked when sending out from the UK?
According to the Royal Mail, all out-going overseas parcels (i.e. anything not letter post) need a declaration of contents.
I'm not an expert, but my advice would be to put "personal medication" on the out-going declaration form, and a low figure for the value, something like £15. This way, there is no deception about the actual contents, and the real-money value is totally arbitrary anyway, as we all know.
In case of problems/questions, it is always a good idea to put the senders address on the back of the parcel. I would guess this also shows good faith as far as transiting customs is concerned, and if anything really gets stuck at least there is a chance you will get your parcel back to the sender. Please see the following (click sending abroad):
Choosing "International Standard" means the parcel will be returned for free if it cannot be delivered. This requires a return address, of course.
For in-coming items to the UK, customs duty is payable, but I believe this is usually waived for anything valued at less than £15. I don't know what the rule is in the US. If the meds came into the UK from abroad, then no dount the UK duty (if any) has already been paid. But I'd guess if any additional US taxes are due, your friend really will not care?
Diagnosed Jan 2015: GT3, A0+F0/F1. Fatigue + Brain-Fog.
Started Sof+Dac from fixHepC 10-Nov-2015. NO sides.
Pre-Tx: AST 82, ALT 133, Viral Load 1 900 000.
Week4: AST 47, ALT 58. VL < 15 (unquantifiable).
Week12 (EOT): AST 30, ALT 26, VL UND
Week16 (EOT+4): AST 32, ALT 28, GGT 24, VL UND
Week28 (EOT+16): AST 26, ALT 22, GGT 24, VL UND
Ever grateful to Dr James.
Relapsed somewhere after all that... Bummer!
Jan 2018: VL 63 000 (still GT3).