▁IM , ▁is ▁the ▁injection ▁of ▁a ▁subst ance ▁directly ▁into ▁mus cle . ▁In ▁medicine , ▁it ▁is ▁one ▁of ▁several ▁methods ▁for ▁parent eral ▁administration ▁of ▁medic ations ▁( see ▁route ▁of ▁administration ). ▁Mus cles ▁have ▁larger ▁and ▁more ▁numerous ▁blood ▁vessels ▁than ▁sub cut aneous ▁t issue ; ▁intr am us cular ▁in jections ▁usually ▁have ▁faster ▁rates ▁of ▁absor ption ▁than ▁sub cut aneous ▁or ▁intr ad erm al ▁in jections . ▁The ▁volume ▁of ▁injection ▁is ▁limited ▁to ▁ 2 - 5 ▁mill il it ers , ▁depending ▁on ▁injection ▁site . ▁ ▁Us es ▁Ex amples ▁of ▁medic ations ▁that ▁are ▁sometimes ▁admin ister ed ▁intr am us cular ly ▁are : ▁ ▁At rop ine ▁ ▁Hal oper id ol ▁( H ald ol ) ▁ ▁A rip ip raz ole ▁( Ab il ify ) ▁ ▁P ali per id one ▁( In ve ga ) ▁ ▁Ch lor prom azine ▁( Th or azine ) ▁ ▁Lor az ep am ▁( At ivan ) ▁ ▁Ful vest rant ▁( F as l ode x ) ▁ ▁Code ine ▁ ▁Mor ph ine ▁ ▁M eth ot re x ate ▁ ▁Met oc lo pr am ide ▁ ▁Mag nes ium ▁sul f ate ▁ ▁Ol anz ap ine ▁ ▁Stre pt om yc in ▁ ▁Dia ze p am ▁ ▁Pred nis one ▁ ▁Pen ic ill in ▁ ▁Inter fer on ▁beta - 1 a ▁ ▁Sex ▁h orm ones , ▁such