Still don't see them.
NAC is for liver support. Very healthy thing to take.
For thyroid you may want to look at TSH, FT3, FT4, RT3 and antibodies.
Take a look at Stop the Thyroid Madnessâ„¢ - Hypothyroidism and thyroid mistreatment
Don't settle for your TSH is "in range" bullshit. Read that link.

Glad to help.