The scientific research on cinnamon has been great in showing that it can be used for blood sugar problems, but it doesn't give a complete picture of cinnamon as a remedy. For example, cinnamon is quite astringent, which means it contracts and tones tissues and has been used to help reduce problems like heavy menstrual bleeding and postpartum bleeding.

It’s important to understand that cinnamon is an astringent because you wouldn’t want to use it by itself if you have an overly dry constitution (dry mouth, dry skin, frequent thirst, and hard dry stools).

Cinnamon is a good remedy for people who feel devitalized and weak. They may feel depressed due to extreme fatigue. Smelling or tasting cinnamon can awaken the fire (yang) energy in a person, motivating them to get up and start doing something about their life. It can also act as a sexual stimulant, arousing passion and sensuality, particularly in men.

Many years ago I watched a documentary about aromatherapy that claimed that the smell of cinnamon enhanced testosterone production in men.  

Cinnamon diluted and taken internally helps to break down bacterial biofilms in the intestinal tract, particularly biofilms from P. aeruginosa and E. coli. 

This means it may be helpful for stubborn bacterial infections in the gut. Reducing harmful microbes in the gut may be part of the mechanism of action in controlling blood sugar, as the type of microbes you have in your intestines influences your food cravings as well as your mood.

You can also use the essential oil topically for skin infections, but again you have to dilute it to avoid irritation. Because of its irritating qualities, don’t use cinnamon oil topically on children.

Since you can't swallow the powder, capsules are a good way to take cinnamon. A capsule will average around 500 mg and a good starting dose is one capsule twice daily for a total of 1,000 mg. If you tolerate it, you can work up gradually to much larger doses, such as 2 or 3 capsules three times daily. You’ll probably tolerate it better if you take it with food, including food that has some fat or oil in it.

You can take cinnamon in a tincture form (1:5) 30-60 drops two or three times a day and you can also make a glycerite out of it. You can also use it to make a tea (infusion) and sweeten it with a little honey or raw sugar. That’s a good way to take it for colds and flu.

My midwife friend, Joan Patton, would put a little cinnamon into a spoonful of olive oil and warm the oil to extract the cinnamon. She would then strain it and use it as warm eardrops to relieve earaches.

If you’re going to use the essential oil internally dilute 1-2 drops of the essential oil in one Tablespoon of coconut or olive oil and take that once daily. Dilute in a similar manner for topical application.