Can't Wash Sunscreen Off? What a 20-Person Trial Found for Water, Cleanser and Cleansing Oil

If sunscreen seems to cling to your face at night, or your pores look more congested after a week of daily SPF, the usual advice is to double cleanse. The research behind that advice is smaller and more specific than the internet suggests. One 20-person trial measured exactly how much sunscreen is left behind by different washing methods, and the answer depends heavily on what kind of sunscreen you wore.

What the one controlled trial measured

The most direct evidence comes from a clinical trial in the Journal of Cosmetic Dermatology (published online in 2019, in print in January 2020). Twenty participants had sunscreen applied, then removed it using water, an aqueous cleanser, or a cleansing oil, and the researchers measured how much sunscreen residue remained.

For a sunscreen that was not water-resistant, residue was 54.0% after water alone, 15.6% after the cleanser and 13.4% after the cleansing oil. The cleanser and oil results were not significantly different from the untreated negative control.

For a water-resistant sunscreen the picture changed. Water left 59.3%, the cleanser left 36.8%, and the cleansing oil left 5.8%, a level not significantly different from the negative control of 3.2%.

What this means in plain terms

Two practical points follow from those numbers.

• Water alone is not enough. Even for an ordinary sunscreen, more than half the product remained after washing with water only.
• A regular face wash did well on ordinary sunscreen, and poorly on water-resistant sunscreen. Roughly a third of the water-resistant product was still on the skin after the aqueous cleanser.

The trial authors concluded that an ordinary sunscreen can be removed by a cleanser or a cleansing oil, while a water-resistant one needs the oil. Keep the scale in mind: this was 20 people, one washing protocol, and specific products. It is a useful signal, not a rule for every formula and every face.

Where the popular advice disagrees

Not every expert reads the evidence the same way. Michelle Wong of Lab Muffin Beauty Science argued, in a post originally published in 2017 and updated in October 2022, that a regular cleanser will remove water-resistant sunscreen, that cleansing oils do not always outperform traditional cleansers, and that double cleansing is gentler but not required. She also noted that some sunscreens may simply need a second wash, and described one study as very limited.

These views are less contradictory than they look. The trial found a regular cleanser removed a large share of ordinary sunscreen but left a meaningful share of the water-resistant type. The Lab Muffin piece is a reminder that formulas vary, that two careful washes can do the work of an oil step, and that none of this needs to become a long routine.

A simple rule for choosing your night routine

Start with the label on the sunscreen you actually wore.

• Ordinary daily sunscreen, no makeup: one thorough wash with a gentle cleanser is a reasonable default, based on the trial results for non-water-resistant products.
• Water-resistant sunscreen, or sunscreen plus makeup: an oil or balm cleanser first, then rinse. If the face still feels filmy, add a water-based cleanse.
• Any sunscreen that still seems to cling: try a second wash before changing products.

Note that rubbing time matters too. In the trial every method was applied with two minutes of rubbing, which is longer than many people spend on a quick rinse. Giving the cleanser time to work is part of why it performed as it did, so a fast splash may leave more behind than the study numbers suggest.

Rinsing, residue and the congestion question

A common worry is that oil or balm cleansers add congestion to skin that already looks shiny. Dermatologist Naissan Wesley, writing in MDedge Dermatology, notes that many balms are labeled non-comedogenic, but that residue from balms that are too thick, or not rinsed off properly, can contribute to comedones or milia. Her practical advice is to massage the balm into dry skin, rinse with warm water, use a wet cloth if that helps removal, and add a second water-based cleanse only if residue remains. She adds that the second step is not necessary for most people.

The same source describes balms as less likely to dry or irritate skin than liquid foaming cleansers. That fits the trial, where 8 participants in the cleanser group reported dry skin compared with 1 in the cleansing oil group. Small numbers, but they point in the same direction.

Cleansing mistakes that make sunscreen feel stuck

Several habits make it harder to get clean without helping at all.

• Cleansing on wet skin. Balms and oils are designed to be worked into dry skin first.
• Rinsing too quickly. Give an oil or balm time to emulsify, then rinse thoroughly.
• Scrubbing harder. Extra friction rarely fixes film; a second gentle wash is usually kinder.
• Layering a heavy product over an incomplete cleanse. Residue then sits under a moisturizer.

The practical takeaway

• The best controlled data we have is one 20-person trial: water alone left more than half of both sunscreen types on the skin.
• A regular cleanser removed most ordinary sunscreen, but about 37% of the water-resistant product remained, versus 5.8% with a cleansing oil.
• Match the cleanse to the product: one wash for ordinary sunscreen, oil or balm first for water-resistant formulas or makeup.
• Rinse balms thoroughly, and add a second water-based wash only if the skin still feels coated.
• If your skin feels tight, stinging or looks irritated after cleansing, simplify rather than adding steps, and check in with a dermatologist if it persists.