Cost: products/vials typically run $199$599 , depending on size and concentration
doi: 10.2217/nmt-2020-0033 241 SamaR
The water itself doesn't "go bad" in a dramatic way, but you can no longer rely on the manufacturer-validated preservative activity
Although some of the natural ingredients used in these patches, such as berberine, have shown in some studies to slightly increase GLP-1 levels, regulate blood sugar levels and promote weight loss 8 , their efficiency through transdermal methods is not yet proven and needs to be studied further 3
People most often notice brighter, clearer skin and a more even tone over a few weeks of regular sessions, not overnight
Not only that but you end up with increased amounts of oxidants which have been linked to accelerate the ageing process