It doesn't do synthesized drugs, with the exception of the False Front's Mimic Signal Drug. Cram is explicitly synthetic by Arsenal's list of complex home cooking chemistry examples, while most of the core book offerings straight out say it.
Drugs I'd consider using constantly:
Betel - limited to mild addiction, and the only downside is the fact you're only getting +1 Perception.
G3 - good for returning from retirement, but not much else.
Red Mescaline - ok ... I wouldn't, but it is apparently natural.
Snuff - the long term effects suck, but in the short term you'll be faster and tougher.
Trance - only if awakened drugs are acceptable and I'm playing a hacker with that paralysis-friendly lifestyle.
It's worth pointing out that even if you do roll well enough to constantly avoid increasing addiction ratings (and increasing dosage requirements), the mechanics explicitly provide your GM with the option of saying, "24/7 bender-man is on his way to burnout status, and going downhill from there". Which makes Betel the only safe choice for addictive substances.