gal⋅van⋅ic

/gælˈvænɪk/ [gal-van-ik]
–adjective
1. pertaining to or produced by galvanism; producing or caused by an electric current.
2. affecting or affected as if by galvanism; startling; shocking: the galvanic effect of his speech.
3. stimulating; energizing: Her galvanic presence brought the party to life.

Remedial is an adjective!

It is incorrect to say, "Do you have remedial?" What we actually mean is "remedial class/lesson", since it is an adjective. Alternatively, you can nominalise it to say "remediation", though that would be a unnecessary mouthful.