11 days, no results yet. Is it possible that the Botox results will appear 'suddenly' any day now, or is it always gradual?

BoTox, and all forms of Botulinum Toxin A, work by blocking the reuptake of acetylcholine at the neuromuscular junction. By doing so, it inhibits transmission of signals from one neuron to the next at whichever junction it is working on (e.g., neuro junction, sweat gland junction, etc.) The duration of BoTox is typically 3-4 months on average. It can take up to 7 days for it to take effect. It it may be that you simply need more BoTox to take effect. Those with very active muscles or I've seen this in men, may need additional units for effect. Thank you for the question! Hope this helps!

Generally, the maximal results from a Botox treatment
are not seen until 14 days post-procedure. However, by 11 days, you should see
most of the effectiveness. 15 units of Botox to treat a frown area in a male is
likely too low, as men usually have stronger muscles that require higher doses
than women. You will likely require more Botox to treat your frown area.

In general, Botox can take around one week to take effect. If you still do not have a visible result after 11 days, I would recommend following up with your provider. I hope this helps, and I wish you the best of luck. 

Typically the male "frown lines" require significantly more Botox than females since males have thicker, stronger muscles in this area. In my experience, 15 units is a very low dose for the male glabella area. You will likely need more Botox to this area. I would recommend returning to your treating physician for evaluation and hopefully a higher dose of Botox will give you a nice result. Best wishes.

I agree that in 3 to 5 days most of my pts see noticeable results. Men do require higher doses. Other possible reason are wrong injection site or antibodies if you have been treated many times previously. Best to go back to your doctor for a review.Best wishes