Uvinul A Plus vs Avobenzone: What Happens When a Label Has Both

Read enough ingredient lists and a pattern shows up. On a US sunscreen, avobenzone almost never appears by itself. There is a second filter listed a line or two below it, and it is there for a reason the marketing copy never mentions. On a Korean sunscreen built around Uvinul A Plus, that second filter is missing. Comparing Uvinul A Plus vs avobenzone usually turns into an argument about which one is stronger, and that is the wrong question. The useful question is which one needs a second filter beside it, and what happens on a label that lists both.

What is actually listed next to avobenzone

Start with labels rather than theory. Anua sells four chemical sunscreens through US retailers, and we read all four FDA Drug Facts panels for our Anua lineup comparison. Every one of them lists avobenzone. Every one of them also lists octocrylene, and two go further and add ethylhexyl methoxycrylene, an ingredient with no SPF number attached to it at all.

Active percentages from the DailyMed Drug Facts panels, read 2026-09-07. Inactive ingredients from the same labels.^[4]

Ethylhexyl methoxycrylene is the tell. It absorbs some UV, but it is not an approved active in the US monograph, so it appears in the inactive list. A formulator does not spend space on it for coverage. They add it for what it does to the molecule above it.

Why avobenzone rarely appears without a second filter

Avobenzone loses potency under UV exposure faster than the other filters around it, and formulators have spent two decades working around that. The most common workaround is octocrylene, and it has been measured directly rather than assumed.

A 2006 study at the University of São Paulo built four SPF 15 filter combinations, spread 40 mg of each onto glass plates, exposed them to UVA and UVB, and quantified what survived by HPLC. The finding on octocrylene was stated plainly:

“OC improved the photostability of OMC, AVB and BP-3.”^[2]

AVB is avobenzone. The same paper ranked the four combinations and put the two octocrylene formulas ahead of the pair without it.^[2]

Ethylhexyl methoxycrylene has the same kind of evidence behind it. A 2021 paper from the same lab tested the effect of three commercial avobenzone photostabilizers on a combination of avobenzone, octyl methoxycinnamate and retinyl palmitate, and reported that adding them “improved the photostability of AVO and RP”.^[3] That is why it shows up on two of the four Anua labels above and nowhere in the coverage claims.

None of this is new framing for us. Our guide to Korean sunscreens with a different US formula already notes that octocrylene is what the reformulated US versions bring in alongside avobenzone. What that piece did not have was the measurement behind it, or the answer to the question that follows.

Uvinul A Plus vs avobenzone in the same formula

This is the reasonable next thought, and it is where the trail goes cold on most ingredient pages. Uvinul A Plus is the trade name for diethylamino hydroxybenzoyl hexyl benzoate, usually shortened to DHHB. It covers the UVA range and it is repeatedly described as photostable. If it holds up under UV itself, the intuition goes, then a formula containing both DHHB and avobenzone should get the best of both.

Someone tested exactly that. The 2017 study, from the same São Paulo group, built three formulations: one with avobenzone, one with DHHB, and one with both. They ran photostability by HPLC and spectrophotometry, then used fluorescence spectroscopy to look at how the two molecules interact. The HPLC result:

“HPLC results demonstrated that DHHB did not present a photostabilizing effect on AVO.”^[1]

And the summary at the end of the abstract, which separates the two claims people tend to merge:

“although DHHB was considered to be photostable for all formulations studied (F2 and F3) it did not increase the photostability of AVO (F3).”^[1]

Photostable is a property of the molecule. Photostabilizing is something the molecule does for a different molecule. DHHB is the first. On this evidence it is not the second.

Two things the study does not say, and we are not going to stretch it into saying them. It reports that all the formulations tested “provided ultra-protection against UVA radiation”, so this is not a finding that DHHB and avobenzone together fail at UVA.^[1] And it measured the singlet excited state of avobenzone by fluorescence, concluding that energy transfer by the Förster mechanism is “unlikely in this work.”^[1] Other proposed routes were outside what it tested.

Why the supplier sheets are easy to misread

Ingredient suppliers publish formulation guides, and a DHHB page is a fair example of how a correct claim turns into a wrong impression. One supplier’s DHHB guide says its stability “improves formulation reliability and reduces the need for complex stabilizing systems”. A separate section lists this among the filter’s advantages: “Helps protect other sensitive ingredients from oxidative damage”. Elsewhere the page names vitamin E and botanical extracts as the ingredients in question.^[6]

Read carefully, those are two claims about DHHB reducing the need for a stabilizer and about protecting vitamin E, not about stabilizing avobenzone. Read quickly, or read as a search snippet that stitches a comparison-table heading onto a conclusion from further down the page, they blur into a claim the document never makes. The 2017 study and the supplier sheet are not in conflict. The study’s own recommendation was that formulations containing DHHB alone “should be considered more advantageous” than formulations containing avobenzone, or avobenzone with DHHB.^[1]

Why these four Korean formulas carry no stabilizer

We opened the ingredient listings for four Korean sunscreens built around DHHB and checked what else was in them. None of the four contains avobenzone, under that name or as butyl methoxydibenzoylmethane. None contains octocrylene or ethylhexyl methoxycrylene either.^[5]

Ingredient listings read on INKEEDecoder (the renamed INCIDecoder) on 2026-09-08. Positions are the ingredient’s place in the full INCI list.^[5]

That is the whole explanation for the missing line. These four formulas have nothing that needs stabilizing, so there is nothing to stabilize it with. It is an absence produced by an absence, not by a superior additive.

What these are like to wear is a separate question from what is in them. One Korean reviewer of the COSRX, who states in the post that they bought it themselves, covers it:

The COSRX reviewer puts the sting down to personal fit rather than the ingredients, and either way it is not evidence about photostability. Our piece on which Korean sunscreens sting and why takes up the ingredient side separately.

One caution before this turns into a rule about Korean sunscreen in general, because it is not one. We went through this in detail in our piece on whether Korean sunscreens stain clothes less, which checked the category rather than four products and found avobenzone in Korean formulas from more than one brand. Korean regulation permits it. Our Sephora K-beauty comparison also turned up a Korean formula using octocrylene for stabilization. Four formulas without avobenzone is four formulas without avobenzone.

Reading this off a label

The practical version fits in three checks.

1. Find the UVA filter first. Avobenzone appears in the Drug Facts actives panel on a US product. DHHB appears in the main ingredient list, usually written out in full as diethylamino hydroxybenzoyl hexyl benzoate, since Uvinul A Plus is a trade name and rarely printed on the box.
2. If you found avobenzone, look for the stabilizer. Octocrylene in the actives, or ethylhexyl methoxycrylene in the inactives. Both have measured photostabilizing results behind them.^[2][3]
3. If a label lists avobenzone and DHHB together, count the DHHB as UVA coverage, not as insurance. That is the one inference the 2017 study rules out.^[1]

Nothing here says avobenzone is a bad filter, and none of it is a reason to throw out a sunscreen you like. A stabilized avobenzone formula is a stabilized avobenzone formula, which is why the stabilizer is in there. Our Tinosorb S vs M comparison covers two of the filters listed alongside DHHB in these Korean formulas, if you want to keep going down the list.

FAQ

Does DHHB stabilize avobenzone?

Not on the evidence available. A 2017 study built formulations with avobenzone, with DHHB, and with both, and reported by HPLC that DHHB “did not present a photostabilizing effect on AVO.”^[1]

Is Uvinul A Plus better than avobenzone?

They are both UVA filters, and the difference that is documented is stability rather than strength. DHHB was found photostable across the formulations tested in that study, and the authors suggested formulations with DHHB alone “should be considered more advantageous” than ones with avobenzone or with both.^[1] Availability is the practical difference for US buyers: DHHB is not in the US OTC sunscreen monograph. All four Anua US formulas use avobenzone for UVA instead.^[4]

What is ethylhexyl methoxycrylene doing in my sunscreen?

Stabilizing avobenzone. It is listed as an inactive ingredient because it is not an approved US active, and a 2021 study measured it and two other stabilizers improving the photostability of avobenzone.^[3] Two of the four Anua US chemical sunscreens list it.^[4]

Do Korean sunscreens avoid avobenzone?

Not as a category, and Korean regulation allows it. The four DHHB-based formulas we opened for this piece contain none of it, but that is a statement about those four products.^[5] We checked the broader question separately in our piece on sunscreen and clothing stains.

Why do the US versions of Korean sunscreens look so different?

They are reformulated for the US monograph, which does not include DHHB or the Mexoryl filters. The replacement UVA filter is avobenzone, which brings octocrylene with it. We compare the two versions side by side in our guide to Korean sunscreens with a different US formula.

Sources

Topics: Ingredient Lists · Korea vs Abroad · All topics