Read here the article, why it’s worth to mix your own deodorant…
The corresponding recipe – There you go:
What you need: sodium bicarbonate, starch (e.g. corn flour), water, some essential oil if you like, empty roll-on bottle or spray flask
How you do it: (a) If you prefer to roll: heat 100 ml of water and add 1-2 tsp starch. Shortly bring to the boil until the mixture becomes slightly condensed. Add some more starch if it is still too fluid. Let it cool down to 30°C and stir in 2 tsp sodium bicarbonate. If you like to have some fragrance then now add a few drops of essential oil. However, this step is optional since the important active ingredient is the sodium bicarbonate (I prefer the simple version without any fragrance). Fill the mixture into a empty roll-on bottle and that’s it! (b) If you prefer to spray: boil 100 ml of water, let it cool down, add 2 tsp sodium bicarbonate, stir to dissolve. Again, add some essential oil if you like. Fill into a spray bottle. Done!
If you tend to sensitive skin or you’d like to have some varieties, you can easily pimp the basic recipe up a bit by adding some other ingredients, e.g. like explained here.