Jojoba oil mixed with vitamin E is excellent for the undereye area - since this skin is the thinnest on the entire body (except for the skin under the tongue), this mixture of oils will help the 'sags'. It will not eliminate them, but help to make them less apparent.
If you prefer, you can always apply your acne medication at night without first applying the jojoba, but keep in mind that the molecules of the mediction are not nearly as small as those of the jojoba; therefore, the medication will not work as effectively since it can only work on the surface of the skin, rather than getting 'into' the skin where the problem lies.