skin damage can take months to heal too. use sunburns for example, which is actually a decent comparison.
"Ultimately, the one thing that will heal your sunburn is time, says Robertson. No product can speed up the process. Even when your sunburn is healed, be careful in the sun, because it will take several months for your damaged skin to return to normal. If you overdo it in the sun while your skin is still healing, your skin will burn faster and be more damaged than before."