I also have tried the NTG ointment. To my knowledge, the only concentration available is that which is used for angina, ie, is a 2% concentration. According to the PDR, this is equivalent to about 15 gms per "inch". From what I recall off the top of my head, the published studies have a product which is a much lower concentration. I have tried it in about 12 patients. I have also tried using it myself so I could tell my patients what to expect. I personally had symptoms of a small fissure, but I didn't not have the diagnosis confirmed by someone else. My own symptoms were relieved promptly, but I did expereince some mild itching and burning, which was less bothersome than the pain. I did experience a dull headache, which was slightly worse than a headache you might get if you stopped taking your usual two cups of coffee in the morning. It lasted most of the morning. I instructed my patients to get as small a dab of the ointment (2%) on the tip of their finger, and apply it once or twice a day, depending on their symptoms and depending on the severity of their headache. I think it is worth a try in patients who are experiencing a lot of pain. The headache is the limiting factor in my limited experience.