How often is it safe to have Dysport injections?

The amount of Dysport you received is less than the typical dose and is probably the reason you are seeing movement.  There is no specific time frame that you need to wait in between injections.  You may want to consider getting a more standard treatment in terms of units and then can expect that the product results will last about 3 months.

The duration of your Dysport treatment will be based on the dosing and the activity of the muscle that you were trying to weaken.   Ultimately every individual will find the optimal dosing to get the result and duration that they are looking for.   One challenge of putting a higher dose in the forehead, is that you may feel heaviness of the brows. This is a delicate balance between duration and desired effect.  

Thank you for your question. 60 U are small dose, may be that is why wrinkles are coming back. With appropriate dose in our practice it works for about 4-6 months at least.

It is not to soon to have more Dysport, however longevity is dose dependent so for that reason maybe a bit higher dosage would be needed as to not have the effects wear off so quickly. Repeat injections do not cause harm or loss of future effect.  Most treatment results last 3-4 months if the ideal dosage is used, this does of course depend on placement and muscle anatomy.

60 units is a relatively low dose for a full forehead and between the brows, so it's no wonder you saw movement. To treat the full forehead, between the brows, and the crow's feet usually 150 units are used. This dose should last about 3-4 months. The less you use the more quickly you will see muscle movement because the effect just doesn't last. "This answer has been solicited without seeing this patient and cannot
be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."