There are over 200 varieties of lavender so it can be easy to make the mistake of cooking with an aromatic lavender instead of one of the preferred culinary lavenders. While there are no health effects, you may be less inclined to cook with lavender again. Aromatic lavenders also contain camphor, a strong flavored compound most well known for its use in cough drops and chest rubs used for congested lungs. The amount of camphor present in lavender is very small, but it will effect the taste of the food you’ve cooked with the lavender. Most likely, you will still be able to eat what you made, but you may not like the results as much as if you had used culinary lavender.
The only other consideration is where the lavender came from and how it was grown. If you use lavender from your garden, and it turns out to be an aromatic rather than culinary variety, there is nothing to worry about. However, if you purchased lavender for use in making aromatic products, the lavender may have been grown using inorganic fertilizers or other chemicals. The chances of this having a dramatic negative effect are almost not worth mentioning, but it is good to be aware of what you eat. Most lavender is grown without the use of pesticides, because there are no insects that eat lavender. However, herbicides and fungicides may be used because lavender that doesn’t get enough sun is susceptible to fungi.
Nonetheless, there is nothing to fear from eating aromatic lavender that has been grown with care. It is possible that some companies add synthetic lavender scent to their lavender products, but it is unlikely that you will find yourself using lavender soap or the lavender from a sock drawer moth bag. You should also never cook with lavender essential oils, as the concentration is very high and essential oils are not made to be food grade. Culinary lavender is the best choice for cooking because of the flavor it adds to savory and sweet dishes.