Serums & Essences · 16/06/2026
The quiet way most people accidentally underdose their vitamin C serum without realising it
Using significantly less product than a formula was actually tested and dosed at — to make an expensive bottle "last longer" — quietly undermines the very results that justified buying the more concentrated serum in the first place.
Why stretching a serum to "make it last" undermines the concentration the formula was actually built around
Skincare formulas, particularly higher-concentration treatment serums, are generally tested and dosed assuming a specific application amount — using meaningfully less than that intended dose, in an effort to stretch an expensive bottle across more applications, delivers proportionally less active ingredient per use than the formula was designed and tested to provide, undermining the very reason a higher-concentration product was chosen over a cheaper, more dilute alternative.
Why this underdosing habit is easy to fall into without consciously deciding to do it
The instinct to use "just a little" of an expensive product, especially when budget-conscious, develops gradually and often unconsciously rather than as a deliberate choice — meaning many people significantly underdose a treatment serum for months without ever explicitly deciding to economise on amount, simply drifting into using less than intended as a bottle starts to feel precious.
Checking actual application amount against the product's own guidance periodically
Periodically check the actual recommended application amount on the packaging or brand guidance, and compare it honestly against how much is actually being used in practice — if there's a meaningful gap, either commit to using the full intended amount or consider whether a less expensive, lower-concentration formula used at full dose might actually deliver more real-world benefit than a premium serum chronically underdosed.
BENTON Vitamin C Serum 30ml — available on BuyBeautyKorea →
