There are contradictory articles about whether disposable feminine hygiene products, even tampons made entirely from cotton, contain dioxin. There's no question that tampons and disposable pads take up a lot of room in landfills. The cost of these products adds up over time. Many women get "diaper rash" from pads. Also, tampons are associated with toxic shock syndrome (TSS).
Reusable menstrual pads (aka "mama cloth") are a safe, green alternative to disposable pads. They can be made from a variety of fabrics and in different sizes and absorbencies (from liners to post-partum). Most have a snap to hold them in place, while some are "lay-in" types. Many women report that their periods are lighter and they no longer experience cramping after switching to cloth pads. If you cloth diaper and/or use family cloth, just launder your mama cloth the same way. Otherwise, you can rinse it in the sink and wash with dark towels.
For women who prefer tampons to pads, there are menstrual cups (Diva Cup, LadyCup, The Keeper, to name a few). Worn internally, menstrual cups catch your flow instead of absorbing it. You may only need to empty it 2 or 3 times a day (maybe every 2 or 3 hours) depending on how heavy your flow is. After emptying, you can rinse it or simply wipe it out, then reinsert it. Between cycles wash with hot soapy water and store it in the fabric pouch that came with it. Menstrual cups come in 2 sizes - one for women who are under 30 and have never had a child, one for women who are over 30 and/or have had a child.
Mama cloth and menstrual cups can last for years. This means far less waste for the planet and more money in your pocket. (You may be surprised at how much a pad or cup costs, but remember it will last for years. You'll pay more up front, but you'll save money over the long run.) They're also healthier for your body. You may think these products sound "gross," especially if this is the first time you've heard about them. They're no more gross than disposable products. I encourage you to seriously think about these alternatives before dismissing them.
For more information...
Green Families Search for "diva cup" and "mama cloth" for TONS of information. From fabrics to troubleshooting, these ladies discuss it all.
iHerb offers both sizes of the Diva Cup. Use the code NEM401 to save $5.
eBay offers the Diva Cup and the LadyCup.
Etsy is a great place to find mama cloth made by work-at-home moms.