Any tips on male infertility?

It seems like my husband might have a thyroid issue. We've been married for 4 years but have been together for 8. We've been trying to get pregnant for 6 years and no luck. I recently got checked and all seems fine on my end. On the other hand, my husband is hesitant to get checked. But anyone have any holistic tips on improving male fertility and thyroid issues. Thanks in advance!