Lubes

For everyday use, water-based lubricant is the most universal choice: it is compatible with latex and with every toy material, rinses off easily and leaves no stains. Silicone lubricant lasts longer and works in water, but should not be used with silicone toys because it attacks the surface. Oil-based lubricants belong only with toys and latex-free condoms.

Water, silicone or hybrid

Water-based lubricants are the default. Silicone lasts longest and stays slippery under water, which makes it popular for anal sex and for the shower — the price is incompatibility with silicone toys. Hybrid lubricants combine silicone's staying power with the lightness of water. Anal lubricants are thicker so they stay in place, because the rectum does not lubricate itself.

What the ingredient list really tells you

Osmolality is the figure almost no pack prints, even though it matters most. The WHO/UNFPA advisory note reports that most commercial lubricants have an osmolality between 2000 and 6000 mOsm/kg, while normal vaginal secretions are 260–290 mOsm/kg. Because strongly hypertonic lubricants can damage the epithelium, WHO recommends a procurement limit of 1200 mOsm/kg, which in practice means no more than 9.9% glycerol or 8.3% propylene glycol in the formulation.

pH: vaginal is not the same as anal

A healthy vagina has a pH between 3.8 and 4.5, while the rectum is close to neutral (pH 7). WHO therefore states that a vaginal lubricant should have a pH of about 4.5 and a rectal one 5.5 to 7 — no single lubricant meets both. If you want one bottle for everything, pick a mid pH and use it generously.