If you are looking to sample strains, the best co-op in the entire Los Angeles area is Cornerstone Research Collective (CRC) in Eagle Rock. Here is their website: http://www.cornerstonecollective.com/ The owner, M, is a researcher and connoisseur who will sit you down at a counter and discuss your condition and different meds and effects. They always ask you what you liked and didn't like from last time so they can make new recommendations. I've gotten to sample stuff at crc that no one else has because strain hobbyists all bring their stuff there. This is the kind of place that stays open 5 minutes late if you are driving from far away and got caught in traffic before a holiday weekend and you give them a call. Parking is kind of tight and it's important not to impose on the residents. CRC is a really important part of the medical community in so cal. Very big ASA supporters.