In the case of a small amount of facial fat filling, the ideal effect can be achieved at one time. But according to the situation you described, your forehead will need more fat filling, so you may need a second "replenishment" filling. The principle of fat filling is "small amount and multiple injections". If too much fat is filled at one time, and the injected fat cannot be supplied with oxygen, induration and calcification will occur, which will lead to the failure of fat to survive, and there may also be "big goose head" and "long life head". Of course, this is not just a matter of autologous fat. To do micro-plastic surgery is to have a certain degree. No matter what you fill in, it is not recommended to inject too much at a time. Generally speaking, 2-3 injections are needed. I hope my answer can help you. Filling the face with autologous fat at one time is not effective. Autologous granular fat is an ideal self-filling material at present, and its implantation has no rejection to the body, but it needs multiple injections to achieve the ideal effect. In addition, there is a small incision in the fat donor area, and the patient needs to experience two invasive wounds. Autologous fat filling is a very common operation in cosmetic department, and it is also one of the facial rejuvenation or facial cosmetic operations that patients are most willing to choose. Because the filled fat comes from itself and there is no rejection, the filled part looks more natural and realistic after filling. However, the biggest disadvantage of autologous fat filling is that the fat has a certain survival rate after autologous fat filling, and it is impossible to survive 100%. After autologous fat is filled, some will be absorbed and some will remain. Whether the effect can be achieved after one time depends on how much fat transplantation survives.