Apple Cider Vinegar for Skin and Complexion: Does ACV Really Clean Pores and Brighten?
Apple cider vinegar for the face: a 1:10 dilution was tested on human skin and irritated 16 out of 22 people. We check the pH of the skin, in vitro evidence, and burn risks.
Apple cider vinegar is making a comeback on the lists of natural remedies for the complexion with three promises: it is supposed to balance the skin’s acidity, inhibit the bacteria responsible for acne, and lighten discolorations. Each of these sounds like chemistry, so it is hard to dispute them without looking at the research. We looked, and it turned out that there is significantly less research than the popularity of this method suggests. The dilution described in guides as safe, that is, one part vinegar to nine parts water, has been tested on human skin and irritated most participants. Below, we separate what has been measured from what is repeated without measurement: what the pH of the skin really is, what laboratory studies have shown, and when vinegar on the face becomes genuinely dangerous.
KEY INFORMATION
• A 1:10 dilution gives 0.5 percent acetic acid, and at this concentration, irritation was reported by 16 out of 22 people (Luu et al., Pediatric Dermatology, 2019).
• In a measurement of 330 people, the natural pH of the skin averaged below 5, not in the range of 4.5 to 5.5 (Lambers et al., 2006).
• The antimicrobial action of vinegar has been demonstrated on a petri dish, not on the skin (Yagnik et al., Scientific Reports, 2018).
• Undiluted vinegar causes chemical burns.
Where did apple cider vinegar come from in facial care?
From the kitchen and from a very old tradition of home compresses, not from dermatology. Apple cider vinegar is produced in two stages of fermentation: yeast convert fruit sugars into alcohol, and acetic acid bacteria of the genus Acetobacter convert alcohol into acetic acid. The suspension of yeast and bacteria, which is visible in unfiltered vinegar, is commonly referred to as the mother of vinegar.
It made its way into cosmetics thanks to three properties of acetic acid, each of which is true and each of which can be exaggerated. Acetic acid does indeed have antimicrobial properties in laboratory conditions. It does indeed lower pH because it is an acid. And it does indeed belong to organic acids, which in high concentrations can exfoliate the skin.
The problem arises when translating these three sentences into a jar of water and vinegar. Apple cider vinegar has an acidity of about 5 percent, and a home tonic diluted one to ten has ten times less, or about 0.5 percent. This is significantly below the concentrations at which it acted in the laboratory on two of the three studied microorganisms. The same raw material in the hair version is discussed in the text Apple Cider Vinegar for Hair, where the same pattern emerges: strong mechanism, weak concentration, lack of studies.
Does the skin really have a pH of 4.5 to 5.5?
Rather lower. A measurement of 330 people showed that after a day without washing and without cosmetics, the average pH of the forearm dropped from 5.12 to 4.93, and the natural value for the skin averages around 4.7, which is below 5. The authors directly oppose this to the widespread assumption of a range of 5.0 to 6.0.
The work of Lambers and colleagues in the International Journal of Cosmetic Science (2006) brings another number that changes the meaning of the entire argument about the tonic. Ordinary tap water, which has a pH around 8 in Europe, raises the skin’s pH and keeps it elevated for up to six hours. The popular saying that the skin returns to its pH in half an hour has no support in this measurement and goes in the opposite direction.
This same work explains why acidic pH is important at all. At a pH of 4 to 4.5, the natural bacterial flora clings to the skin, and at an alkaline pH of around 8 to 9, it begins to detach from it. Skin with a pH below 5 also performed better in barrier, hydration, and exfoliation measurements. This is an argument for gentle cleansing, not for pouring acid on the face.
Separately, it is worth dismantling another popular mechanism. Pores do not open and close because they have no muscles: they are openings of sebaceous glands. Their visibility depends on the amount of sebum and the inflammatory state around the follicle, not on the pH of the water you wash your face with.
What did the only study of diluted vinegar on human skin show?
That it does not improve the skin barrier and irritates most subjects. Luu and colleagues (Pediatric Dermatology, 2019) examined exactly this dilution, which guides claim is safe. Participants soaked one forearm in a solution of 0.5 percent acetic acid and the other in water, for ten minutes daily for fourteen days.
There were 22 participants: eleven with atopic dermatitis and eleven healthy. Trans-epidermal water loss increased, and pH dropped immediately after the treatment, but after an hour both effects disappeared. Mild adverse effects were reported by 16 out of 22 people, or 72.7 percent, and subsided after discontinuation. The solution was prepared by mixing one part vinegar with nine parts water, which is the proportion that the internet calls mild.
The same team repeated the study in 2021 with 16S sequencing and checked whether vinegar changes bacteria on the skin. It did not change: neither the composition of the microbiome nor the number of Staphylococcus aureus. The 2021 study was funded by the University of Virginia along with three of its own units, not by the vinegar manufacturer, so its result cannot be explained by the interests of the cosmetics industry.
| Study | On what | Result |
|---|---|---|
| Luu et al. 2019 | 22 people, forearm, 14 days, 0.5 percent | No improvement in barrier, irritation in 16 out of 22 |
| Luu et al. 2021 | The same group, 16S sequencing | No changes in microbiome and Staphylococcus count |
| Yagnik et al. 2018 | Laboratory cultures, no human involvement | Inhibition of growth, but at acidity from 0.1 to 5 percent |
Does apple cider vinegar have antibacterial effects on the skin?
On a petri dish, yes, but it has not been demonstrated on the skin. The most frequently cited work on this topic (Yagnik et al., Scientific Reports, 2018) examined three microorganisms and indicated how strong a solution was needed to inhibit their growth. These dilutions disappear in summaries from guides.
We take numbers from the results section, as the summary of the same work provides different values for two species. To inhibit the growth of the yeast Candida albicans, undiluted vinegar with an acidity of 5 percent was needed. For Staphylococcus aureus, a dilution of half, or an acidity of 2.5 percent, was sufficient. The most sensitive was Escherichia coli: its growth was inhibited by a fifty-fold dilution, corresponding to an acidity of 0.1 percent. A home tonic has about 0.5 percent, so it exceeds the threshold only for one of the three species, while for the other two it is several times too weak. The authors also observed a decrease in the secretion of inflammatory cytokines in cultures with monocytes and declared no conflict of interest.
Two things that circulate with this work are not present in it. Methicillin-resistant Staphylococcus appears only in the introduction, in the description of the problem of antibiotic resistance, and the common Staphylococcus aureus was studied. The bacteria Cutibacterium acnes, which is associated with common acne, does not appear in the full text at all. Therefore, the leap from this work to a conclusion about acne is a jump over a species that was not checked here.
In fact, the measurement in humans resolves this, and we already have it. Since fourteen days of daily soaking in vinegar did not change either the composition of the bacterial flora or the number of Staphylococcus, it is hard to expect such an effect from wiping the face with a cotton pad. The skin has a stratum corneum, which a petri dish does not have.
When is apple cider vinegar on the face dangerous?
Always when it comes into contact with undiluted skin, and with a damaged barrier also when diluted. Chemical burns from vinegar have been described in the dermatological literature at least three times, including in a newborn. These are not reports of rare allergies, but of the corrosive action of concentrated organic acid.
Korkmaz et al. (Pediatric Dermatology, 2000) described a burn in a newborn to whom vinegar was applied to the skin to reduce fever. Bunick et al. (Journal of the American Academy of Dermatology, 2012) described a burn after local application of apple cider vinegar. Feldstein et al. (The Journal of Clinical and Aesthetic Dermatology, 2015) described a burn in a person who removed moles with vinegar according to instructions found online.
Diluted vinegar is not a safe version of the same. In the Luu study, it irritated the skin of nearly three-quarters of participants, including healthy individuals, with just ten minutes of contact daily. In the case of active skin inflammation, after exfoliating treatments, and with disrupted continuity of the epidermis, the use of anything acidic is decided by a dermatologist, not a guide.
If you are looking for gentle care, a more sensible direction is a moisturizing cream with a simple composition. What a hemp cosmetic can do and what it cannot do is discussed in the text Hemp Cream for the Face, and a broader overview of ingredients and recipes has been gathered in the text Hemp in Cosmetics.
Frequently Asked Questions
Does apple cider vinegar clean pores?
We did not find a study that demonstrated this. Pores are openings of sebaceous glands, they do not have muscles and do not close in response to pH. Their visibility depends on the amount of sebum and the inflammatory state around the hair follicle, not on the pH of the rinsing water.
Is a 1:10 dilution safe for the face?
This is the exact concentration studied by Luu and colleagues (2019): 0.5 percent acetic acid. Mild irritation was reported by 16 out of 22 participants, or 72.7 percent, including among those with healthy skin. Calling this dilution safe has no basis in the only measurement that exists.
Does apple cider vinegar lighten discolorations?
We did not encounter a study in humans that verified this. Acetic acid belongs to organic acids, but in a home tonic it is diluted to about 0.5 percent, which is ten times weaker than vinegar itself. Mere belonging to the group of compounds is not evidence of action.
Does apple cider vinegar fight acne bacteria?
The bacteria Cutibacterium acnes were not studied in the most frequently cited work on vinegar (Yagnik et al., 2018), which included Escherichia coli, Staphylococcus aureus, and the yeast Candida albicans. In humans, fourteen days of soaking in vinegar did not change the composition of the skin’s bacterial flora (Luu et al., 2021).
Can apple cider vinegar burn the face?
Undiluted, yes. Chemical burns from vinegar have been described at least three times: in a newborn (Korkmaz et al., 2000), after local application of apple cider vinegar (Bunick et al., 2012), and after self-removal of moles according to instructions found online (Feldstein et al., 2015).
What is the natural pH of the skin?
On average below 5, not from 4.5 to 5.5. In a measurement of 330 people, the average dropped from 5.12 to 4.93 after a day without washing and cosmetics, and the natural value is estimated by the authors to be around 4.7 (Lambers et al., 2006). Tap water raises this pH for up to six hours.
Apple cider vinegar is available in the store at Bucha exclusively as an oral supplement, there are no cosmetics with vinegar or tonic there. Face and body creams are gathered in the creams category (as of August 16, 2026).
This article is for informational and educational purposes and does not replace consultation with a doctor. If you are pregnant, breastfeeding, taking medications, or have chronic conditions, consult the use of supplements or herbs with a specialist.
Author: Michał Waluk · Published: 2026-06-22 · Updated: 2026-08-16
