Short story: The effect you wish to achieve will also determine the method of dosing.
Long Story: Most people report a difference in symptom relief depending on the method of delivery.
Sublingual: Given in small amounts under the tongue or in cheek (buccal). This method absorbs the medication into the blood stream via mucous membranes. This is why it is advised to rub sugar on a diabetic’s gums if they go into a seizure. This method also bypasses the stomach and digestive system.
Good for those with difficulty processing drugs (like my daughter). Very easy to dose if using an oil that is concentrated to a level of only a few drops. The dose is so small it does not have enough mass to even swallow. It is often a more accurate method of dosing compared to oral.
Oral: Swallowed or put on, or in, food or beverage to be ingested. This method is the easiest for many kids. You can easily hide the meds. They do enter the stomach and digestive system. Not best for anyone experiencing digestive issues or on a gut-health diet like GAPS or similar. This may also treat some symptoms differently. When ingested, THC tends to give an overall body “high” vs a mental “high”. I use these terms for lack of better ones. Oral medication is great for kids with cancer (not only to help eliminate the cancer itself but relieve symptoms of chemo and radiation), loss of appetite, perhaps body tremors, etc. Also may be easiest for G-tube feedings.
Rectal: Arguably the best place to quickly absorb medication due to the mucous membranes. Again a quick uptake to the system. Any cancers of the lower digestive tract will benefit from this method. Many parents prefer its quick onset. But if your child is older and does not like the sensation it could be an automatic out.
Vaginal: Usually not for children, but many women with cancers or other diagnoses of the uterus, ovaries, etc will benefit from this method of delivery.