It should tell you on the bottle. If it has a use by date and doesn't say "once opened use within..." go by the use by date.
Under the right circumstances, it can be kept FOREVER.
30 days
You can get whooping cough (pertussis) multiple times throughout your life, as immunity from the disease or vaccination decreases over time. Generally, the immunity from natural infection or vaccination diminishes after about five to ten years. Therefore, it is possible to contract whooping cough more than once, especially if booster vaccinations are not kept up to date.
Once your dog has completed treatment for Kennel Cough, it can continue to infect other dogs for 6-14 weeks. Being vacinated for Kennel Cough does not guarantee complete protection (no vaccine guarantees complete protection) but it will lower the chance of infection.
Scotch that has been opened will last indefinitely if kept in a cool dark place.
On your ointment container it will tell you the date of when it goes bad. if not i suggest you go to a pharmacist.
Cheetahs were once kept by people for use in hunting.
Penicillin lasts as long as three years when it has not been used. Once the mixture has been prepared, it will last for only seven days.
You will eventually die of a terrible cough and chills.
how long can you leave haggis in freezer
Once they hatch, platypus offspring are kept safe in a nesting chamber at the end of a very long burrow.
he kept the bank of the united states which he had once oppose