If your local store does not supply them, demand that they do. Demand products with reduced packaging. That's a lot of clout. Write letters to your government or MP asking for stricter control over menstrual products. Currently, they fall into a loophole where there is little regulation.
Any company can put out their product without proper testing.
Tell your friends what you know and how you feel. Menstruation is a cool part of some woman's life. Don't hide it. Talk about it. Switch to better, more ecological products.