I did this after some discussion with my wife, who has a biochemistry degree and is a current med student.
Menthol is a skin permeability enhancer, allegedly aiding absorption into the skin. It’s commonly used in products to aid permeability for the delivery of medicines, such as anti-inflammatories. Given the ingredients of Amp, it appears that they are looking to rapidly enhance the absorption of sodium bicarbonate as a lactate buffer by way of menthol. Sooo… I simply went out and made my own, experimenting with various concentrations of menthol and sodium bicarbonate in a pre-made hypoallergenic lotion. The final “product” I’ve settled on has more menthol than Amp, and is a bit grittier - I lack the same technology to mix a suspension, and probably added more sodium bicarb.
I compared the two back to back - extremely similar and noticeable results. My own concoction has more of a cooling feel, and is considerably less slippery, however does leave a gritty residue. Obviously, YMMV, but this isn’t a terribly difficult product to copy at home with a little understanding of skin barriers/biochemistry.
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