Can anything shrink your pores?

The claim

Toners, masks and "pore-minimising" products tighten or shrink pores.

What the evidence actually shows

Pores are follicular openings, and their visible size is determined by what is coming out of them and by the structure around them.

A study in the British Journal of Dermatology measured 60 volunteers and found pore size independently predicted by sebum output level - the strongest factor - plus male sex and age, with additional hormonal and menstrual-cycle effects in women. A later review in the Journal of Cosmetic Dermatology lists the determinants as age, sex, genetics, UV exposure, ethnicity and sebum secretion.

None of those is addressed by an astringent. Cooling or alcohol-based products cause transient tightening of surrounding skin and a temporary appearance change, which is why the claim survives - something does briefly happen.

What does produce measurable reduction, per the same review, is intervention on the actual determinants: topical retinoids, oral antiandrogens, chemical peels and fractional lasers, with one CO2 laser study showing a 54.5% reduction in pore measures. Those work by suppressing sebum output or remodelling the surrounding dermis.

What to do instead

If pore appearance matters to you, the evidenced levers are sebum control and dermal remodelling - a retinoid, sun protection to preserve the surrounding support structure, and for larger changes a clinical procedure. Keeping pores clear also helps appearance, since a pore filled with oxidised sebum reads as larger and darker than an empty one.