My methrotrexate i take for rhem arth is now contains preservatives. does this change the effectiveness? i don't think the medication is helping me as much as before.

Should : Should not make a difference but i would speak to a rheumatologist about this.

No, : No, the effectiveness should not be changed. Preservative is usually put into the larger multi-use vials of Methotrexate to reduce the risk of bacterial contamination but may not be in the smaller single-use vials as they are thrown away after a single injection.

The : The preservative will not decrease the effectiveness of methotrexate.