Lubricants can make sex and masturbation much more enjoyable, particularly when you don’t need to re-apply during the act. Many lube users ask how long their products will last, and there’s two questions here: one relates to the expiration date of lube, and the other addresses the sustainability of the slippery, smooth feelings.

Fortunately, modern formulas excel in both areas. If you’re looking to find a long-lasting lubricant, here’s what you need to know.

Picking a Lube for Long-Lasting Slickness

Manufacturers design their lubricants to last for a long time during sex, but there are some fundamental limitations for different types of ingredients. Your experience will vary depending on how you use the lubricant, how much you apply, and environmental factors (for example, whether you’re in an especially humid or dry room).

Oil and silicone-based lubricants usually last longer than water-based products. They’re not easily water soluble, and they don’t absorb into the skin or evaporate easily. This is part of the reason that they’re somewhat slicker than water-based lubricants; they’re more adept at preventing friction, since more of the lubricant remains in place during sex or masturbation.

This also means that these products are fairly difficult to clean up, and oil-based lubricants can also degrade latex condoms, greatly increasing the chances of breakage. Silicone lubricants can damage silicone sex toys in a matter of seconds, but they are completely safe to use with latex condoms.

While water-based lubricants don’t provide smoothness of the other two options, many have additives that allow them to last for a long time during sex. Moisture-retaining agents like aloe vera, hydroxypropyl and glycerin are examples. Water-based lubes still evaporate fairly quickly when compared to the options listed above, but they’re much easier to clean up.

Lubricant formulas vary from one manufacturer to the next, and there’s no tried-and-tested rule for picking out a lubricant that will stay slick. Silicone and water-based lubes are typically considered the best options, since they’re safe for condoms; hybrid lubricants, which consist of a specially formulated blend of water and silicone, offer long-lasting lubrication with easy cleanup.

What to Know About Expiration Dates

As for expiration dates, they’re certainly worth your attention. Most lubricants contain preservatives–citric acid, phenopip, propylene glycol and phenoxyethonal are common examples–and these ingredients become significantly less effective over time. This causes the pH to drop, and eventually, bacteria and fungi can take hold.

The good news is that the antimicrobial agents in water and silicone lubes tend to work for years at a time, so most lubricants don’t have a strict expiration date. They also won’t degrade significantly until exposed to air, so closed bottles are generally safe. Always keep your lube at room temperature and don’t open the bottle until you’re ready to use the product.

You’ll get plenty of uses out of a single bottle, and most products will last for quite a while if you store them properly. Even so, you should throw away lube bottles after about a year. Avoid buying excessively large bottles and try to choose a size that you’ll go through in that time frame. Some lubricants may advertise an expiration date, which is a good number to go by; however, don’t take chances if you notice a change in the color or texture of the product.