'anti-medication' is a compound formed from the Greek prefix 'anti-' meaning 'against' and the modern English noun 'medication', which itself derives from Medieval/Latin roots meaning 'treatment' or 'healing'.

'medication' comes from Medieval Latin 'medicatio' (from Latin 'medicare' / 'medicus') meaning 'treatment, healing', which passed into Old/Middle French and then into Middle English as forms like 'medicacioun' before becoming modern English 'medication'. The prefix 'anti-' is from Greek 'anti' and has been used in English compounds since the early modern period; combining them as 'anti-medication' is a modern English compounding for expressing opposition to medication.

Originally the components meant 'against' and 'treatment/medicine'; combined, the term has come to mean 'opposition to the use of medicinal drugs' or describe those who hold such a position.