^ Yes Baclofen acts on GABA-B receptor sites like GHB does but it is actually more quite similar to phenibut, but is a much safer substance, It would be my muscle relaxant of choice and it does have some recreational value to it.
^it;s more a "potentiator/synergistic" drug rather a recreational drug, imo. taking too much iof this drug is quite uncomfortable; complete loss of motor functions including no balance, confusion to a low degree and an uncomfortable feeling of the shakes. these are my experiences from taking any more than 100mg+ in one dose. 75mg seems the sweet spot for me.
works nice as an anti-anxiety med for myself in lower doses - 50-62.5mg
do try to avoid poly dryg use, mainly other gabaergics (benzis, alcoho, etc), more potent opiates in higher doses and any other sedative/tranqs.
IME I don't know why you would want to. I'm Rxed 10mg Baclofen and even if i take 40-60mgs I really don't get much good effects that would make me want to even consider IV. But it is quite useful when in combination with opiates or to take some on an stimulant comedown or even just for sleep at night.