Lemons are a flavorful addition to many dishes and are also commonly used for fresh lemonade or to add zip to iced tea or ice water. Because the fruit's seeds are small, it can be difficult to avoid ingesting one or two on occasion; while they can be bitter, lemon seeds are not considered dangerous.
Like limes, lemons are an excellent source of vitamin C. They also contain antioxidant and anti-cancer properties.
Apple seeds, cherry stones and nectarine, peach and plum pits are considered poisonous if consumed in large enough quantities. They contain a form of cyanide, a substance lethal to humans.
Lemon seeds are not in the same family as apple, cherry or other stone fruits and are not considered dangerous.
While there is nothing inherently dangerous in lemon seeds, they migt bother people with digestive disorders, such as irritable bowel syndrome or diverticulitis.
The ASPCA says lemon seeds are not poisonous for dogs to consume, although they could possibly also cause digestive problems for canines.