Slow leak in A/C Condenser on 2003 Pontiac Grand Am

I'm losing refrigerant slowly through a leak in my condenser. A refill lasts about 6 weeks. Is there a refrigerant out there with a sealant in it? Or is there a way to seal the leak externally to slow it even further?

There are some A/C "sealers" out there. If they really work or not that is hard to say. You can purchase refrigerant with sealer in it or the sealer is also available separately. The condenser in your 2003 Pontiac Grand Am should not be that difficult to replace. You will probably save money in the long run by replacing the the condenser instead of trying to seal the leak in the old one.