I use black seed oil. AKA black cumin. Comes in pills and straight oil.

Anywhere from a teaspoon to a tablespoon a day will do. In the capsule form, 2 to 4 a day.

I've used if for several years now. If you miss a day or a few days even, you'll still be okay.

You can find it just about everywhere now... Here's the brand I've been using:
[link to www.amazon.com]