Originally Answered: How long will it take to tone up extra skin?
The word "tone" has not definition in the context you used so I'm going to assume you mean "tighten". Also, you left out a crucial bit of information. Your age.
When people lose substantial amounts of body fat, the skin may become loose. Whether the skin will tighten after fat loss will depend on many things. However, two predominate.
1. Stretching only - If the skin is loose because it was stretched but not beyond it's natural elasticity, it will tighten of its own accord over time. That process will happen in a few weeks to months.
2. New skin cells - If the skin was stretched beyond it's natural elasticity, it will have grown new skin cells in response to the tension. And, when new skin cells have been added, they will not go away when the fat is lost. In that case, the skin may remain loose.
It may help you to appreciate the amount of new skin growth of which the body is capable if you go here --> http://www.circumstitions.com/Restore.ht… and compare the pictures of the before and after pictures of penis foreskin restoration.
Fat distribution also plays a role in the loose skin problem. If the fat loss was predominantly in one area (eg: the waist area), the skin will have stretched more than if the fat loss was more uniformly distributed over the body. People who have lost most of the fat from one area will be more likely to have residual loose skin than those who lost a small amount of fat from a wide area.
In most cases of nominal (not extreme) fat loss, both 1. and 2. may apply. In other words, the skin may tighten somewhat and remain slightly looser. Because elasticity decreases with age, in older people it is more likely the skin will remain loose for a given amount of fat loss. And, of course, the greater the fat loss, the more the skin has been stretched and the less likely it will be to return to the same tightness it had prior to the fat gain.
As a crude rule of thumb, a young person who loses only <30% of their weight will not have loose skin. Those losing 30-60% of their weight will likely have some loose skin. And those who lose >60% will probably have undesirable loose skin.
Loose skin which does not resolve naturally cannot be tightened. It must be removed surgically. There are no wraps, creams, spa treatments, drugs, chemicals, herbals, etc. that can make skin shrink. However, adding muscle to increase body volume can help tighten the skin.
If you are young, as you seem to be, and have lost about 30% of your weight, you will probably not have much loose skin after a few weeks. It may take a bit longer depending on many things including genetics, diet, changes in lean tissue mass (muscle), how long the excess fat was maintained, etc.
For more about post-fat loss skin, go here --> http://www.livestrong.com/loose-skin-aft… .However, bear in mind that fact that most of those things said in the Mayo Clinic articles refer to very small amounts of amelioration. For example, losing fat slowly will help prevent loose skin but not by much. It is always important to be aware of whether the information you are given is qualitative or quantitative.
Good luck and good health!!