pH is on the front of half the products in this category and explained by almost none of them. It is worth ten minutes, because once you understand what it actually is, most of the marketing stops working on you.
In this article
- What pH is, in one paragraph
- The healthy range
- What keeps it there
- What pushes it up
- Why a higher pH matters
- The vulva is a different number
- What actually restores it
- Testing at home
- Frequently asked questions
What pH is, in one paragraph
pH measures how acidic or alkaline something is, on a scale from 0 to 14. Seven is neutral, water. Below seven is acidic, lemon juice is about 2. Above seven is alkaline, bleach is about 13.
The part that matters: the scale is logarithmic. Each whole number is a tenfold change. A pH of 4 is ten times more acidic than 5, and a hundred times more acidic than 6. So small-sounding differences are not small.
The healthy range
A healthy vaginal environment sits at a pH between roughly 3.8 and 4.5, with reports averaging nearer 3.5 and moving within that band across the menstrual cycle.
That is meaningfully acidic. More acidic than coffee.
It is supposed to be. The acidity is not a side effect, it is a defence.
What keeps it there
Lactobacilli. These are the dominant bacteria in a healthy vaginal environment, and they metabolise glycogen from vaginal cells into lactic acid.
That lactic acid is what holds the pH down. And the low pH is what keeps lactobacilli dominant and other organisms suppressed. It is a self-reinforcing loop, which is why it recovers on its own most of the time, and why it is unstable once it tips.
Estrogen matters here too, because estrogen drives the glycogen supply the lactobacilli feed on. Which is why pH tends to rise after menopause, and why dryness and pH changes arrive together rather than separately.
What pushes it up
Everything on this list is alkaline, or removes the bacteria producing the acid, or both.
- Menstrual blood, around pH 7.4, which is why the environment shifts during a period
- Semen, around pH 7.2 to 8
- Douching, which physically removes lactobacilli
- Soap, at pH 9 to 10
- Antibiotics, which do not distinguish between bacteria you want and bacteria you do not
- Falling estrogen in perimenopause and beyond
- Coconut oil and most plant oils, which sit around pH 7 to 8
Most of these are unavoidable and the system handles them. Periods and sex happen and pH returns. The problems arise with the ones that repeat daily, or that remove the bacteria rather than just adding an alkaline substance.
Why a higher pH matters
When pH rises, lactobacilli lose their advantage and other organisms gain one. That shift is the underlying event in bacterial vaginosis, which is a change in the bacterial population rather than an infection caught from outside.
Symptoms usually follow the shift rather than the other way round: odour that is new or fishy, changes in discharge, sometimes irritation. If that is where you are, the fuller picture is here.
Worth being precise about one thing: a raised pH is a condition, not a diagnosis. It makes some things more likely. It does not tell you which one.
The vulva is a different number
Almost every article on this topic collapses the two, and it leads people to buy the wrong things.
| Surface | Approximate pH |
|---|---|
| Vaginal canal | 3.5 to 4.5 |
| Vulvar skin | around 4.7 |
| Skin elsewhere | around 5.5 |
| Bar soap | 9 to 10 |
The vulva is external skin. It is more acidic than the rest of your body but not as acidic as the canal, and it is maintained by skin biology rather than by lactobacilli.
This is why an external cleanser and an internal product are different categories, and why "restores your pH" on an external wash is a claim to read carefully. External washing does not need to change vaginal pH, and the evidence indicates appropriately formulated vulvar washes do not change the pH or microbiome of the vulva either. Not changing anything is the correct outcome for a cleanser.
What actually restores it
Honestly, and this is the part product marketing avoids.
Mostly, it restores itself. The loop is self-reinforcing. Remove what is disrupting it and the population usually recovers.
Stop the repeating disruptions. Douching, soap, scented products, overwashing. This is the highest-value action and it costs nothing. The practical version is in should you wash your vulva.
For an established bacterial shift, see a clinician. Bacterial vaginosis is usually treated with prescribed antibiotics. No wash resolves an established case, and products claiming to are overreaching.
Support rather than override. Prebiotic approaches work by supporting beneficial flora rather than stripping or acidifying, which is the more defensible mechanism for an external product.
And keep the barrier intact. Skin that is dry and cracked is easier to irritate and slower to settle, which is where an external balm does its actual job. Not changing pH, maintaining the barrier.
Testing at home
pH test strips are sold for this and they are cheap. They are also of limited use.
A raised reading tells you something has shifted. It does not tell you what, and readings are easily confounded by recent sex, a period, or recent washing. A normal reading does not rule out yeast, which typically occurs at a normal pH.
Useful for: noticing a pattern over time. Not useful for: deciding what to treat.
Frequently asked questions
What is a healthy vaginal pH?
Roughly 3.8 to 4.5, with reports averaging nearer 3.5, moving within that band across the menstrual cycle. It is more acidic than coffee, and the acidity is produced by lactobacilli converting glycogen into lactic acid.
What causes high vaginal pH?
Menstrual blood, semen, douching, soap, antibiotics and falling estrogen are the common causes. Most are temporary and the environment recovers. Repeated daily disruption, or anything that removes lactobacilli rather than simply adding an alkaline substance, is what causes lasting change.
Can I fix my pH with a product?
Not reliably, and be cautious with products claiming to. The environment is self-regulating, and the effective action is usually removing what is disrupting it. For an established bacterial shift, prescribed treatment is what resolves it.
Is vaginal pH the same as vulvar pH?
No. The canal sits around 3.5 to 4.5, maintained by lactobacilli. Vulvar skin sits around 4.7 and is maintained by skin biology. They need different products, which is why external washes and internal products are not interchangeable.
Does a high pH mean I have an infection?
No. It means conditions have shifted in a way that makes some things more likely. Bacterial vaginosis is associated with raised pH, but yeast typically occurs at a normal pH, so a normal reading rules very little out.
Do probiotics help vaginal pH?
The evidence is mixed and depends heavily on strain, dose and route. Prebiotic and probiotic approaches are plausible and actively researched rather than settled. They are reasonable as support and not as treatment for an established case.
Sources
- Vaginal and vulvar pH ranges, and vulvar wash tolerance and microbiome data: PMC7168340
- Douching and associated risks: ACOG