Lubricant, and why it matters more than people think

Lubricant is treated as an admission that something has gone wrong, which is both untrue and the reason a lot of avoidable discomfort and injury persists.

Why natural lubrication varies

It is not a straightforward index of desire.

It varies with cycle phase, hormonal contraception, breastfeeding, menopause, dehydration, medication including antihistamines and antidepressants, arousal duration, anxiety, and time.

Which means that a person can want sex and not be lubricated, and can be lubricated and not want sex — the correlation is far weaker than popular understanding assumes, and the mismatch causes a great deal of unnecessary interpretation.

The practical response is a bottle rather than an inference.

Why it matters medically

Friction causes microtrauma to genital and anal tissue.

Microtrauma is uncomfortable, increases susceptibility to infection, and makes subsequent sex more likely to hurt, which establishes a cycle.

Adequate lubrication reduces condom breakage and slippage, which is a direct contraceptive and infection-prevention benefit.

And for anal sex, where there is no natural lubrication at all, it is not optional.

The types

Water-based is the general-purpose choice: compatible with all condoms and all toys, easy to wash out, and it dries out, requiring reapplication or reactivation with water.

Silicone-based lasts considerably longer, does not dry, is excellent in water, and is compatible with latex condoms — but degrades silicone toys, so the two should not be combined.

Oil-based including natural oils lasts well and destroys latex condoms, which is the critical point.

Oils in the vagina are also associated with disturbance of the microbiome in some evidence.

Hybrid products combine water and silicone.

Petroleum jelly and household oils are not suitable for use with condoms and are poorly suited to internal use generally.

Osmolality and pH

The technical point that most product marketing ignores and that actually matters.

Osmolality describes the concentration of dissolved substances relative to body tissue.

Highly hyperosmolar lubricants draw water out of the cells lining the vagina and rectum, causing tissue damage that has been demonstrated in laboratory and clinical studies.

The World Health Organization has published guidance recommending that personal lubricants have an osmolality below a specified threshold, and a large number of widely sold products exceed it substantially — some by an order of magnitude.

Glycerin content is a common driver of high osmolality and has also been associated with yeast overgrowth in some people.

Vaginal pH is naturally acidic and rectal pH is closer to neutral, and products markedly outside the appropriate range can be irritating.

The practical advice: look for products describing themselves as iso-osmolar or body-matched, and be suspicious of anything with a long ingredient list of warming, tingling or flavouring agents.

What to avoid

Warming, cooling and tingling products, which achieve their effect through irritants and which cause problems for a substantial number of people.

Flavoured products used internally, which frequently contain sugars.

Anything containing nonoxynol-9, a spermicide once promoted for infection prevention and now known to damage epithelium and increase HIV susceptibility with frequent use.

Numbing products marketed for anal sex or for delaying orgasm, which remove the signal that prevents injury.

And household substitutes generally, which are not formulated for the purpose.

Moisturisers versus lubricants

A distinction that matters for anyone with persistent dryness.

Lubricant is used at the time and works mechanically.

Vaginal moisturiser is used regularly, several times a week, and works by rehydrating tissue over time.

For menopausal or postnatal dryness, moisturiser addresses the underlying tissue state and lubricant addresses the moment, and using both is standard advice.

Local vaginal oestrogen goes further and treats the cause where the cause is hormonal, and is appropriate for many people including some who cannot take systemic hormones.

The conversational bit

Which is the actual barrier.

Introducing lubricant is frequently read by one partner as evidence that the other is not aroused, which is why it goes unused in couples who would both benefit.

Framing it as something that makes things better rather than something that fixes a deficiency changes that conversation entirely.

And in practice, most people who start using it report that it improves sex generally rather than only in the situations they bought it for.

General information only, not medical advice. Consult a qualified clinician about persistent dryness or discomfort.