A reader emailed me this question:
I have been finding conflicting information even among reputable sources on whether toners serve any purpose or what they're supposed to be used for. I like using a gentle toner for my oily skin, but what I'm wondering is whether it's alright to apply with a spray bottle instead of a cotton pad. Would spraying instead of wiping it on defeat the purpose?
This is actually a pretty interesting question!
Back in the bad old days of skincare, cleansers were formulated at a high pH. We now know that skin functions best at a bit below pH 5 (slightly acidic) - a cleanser with a high pH would throw your skin off-balance, leading to issues like irritation, dryness, chapping and breakouts. To fix this issue, toners were introduced to adjust the skin's pH back to its happy place.
However, research happened, and now most cleansers on the market these days are actually on the acidic side of the spectrum. So technically, a toner isn't necessary. But it can be a handy in-between step! How you should apply your toner really depends on what you're using it for.
Cleaning off the last traces of make-up, dirt or cleanser - Cotton pads are the way to go, so you'll actually get the unwanted stuff off your face and onto the pad.
Adding active ingredients e.g. salicylic acid, glycolic acid, vitamin C - Both spray or cotton pads will work well, as will dabbing it on with your fingers.
Balancing pH - If you have a cleanser with a high pH and you don't want to let go of it for whatever reason (though you totally should!), wiping or spraying will work.
Closing your pores - Pores don't actually open and close significantly - if you use an astringent, the skin around the pore will temporarily squeeze the pore shut, either through irritation or drying out the skin, both of which aren't great for your skin long-term, and your pores will come back in a matter of minutes anyway. But if you really really want to do this, again, either way will work.
Additionally, cotton pads will tend to absorb more product though, so dabbing or spraying are thriftier options, and they're more environmentally friendly as well!