* Chemical Bonds are Broken and Re-formed, But Not Permanently:
* Perms work by using chemicals to break the disulfide bonds in the hair's keratin structure. These bonds are what give hair its natural shape.
* After breaking the bonds, the hair is reshaped around rods or rollers.
* A neutralizer is then applied to reform the disulfide bonds in the new shape.
* While the bonds are reformed, they are not as strong or as perfectly aligned as they were naturally. They are also constantly under stress from daily styling, washing, and environmental factors.
* Hair Growth:
* Your hair is constantly growing. As new, unpermed hair grows in at the roots, the difference between the permed and unpermed sections becomes more apparent. This isn't the perm "washing out" but rather new hair growing in its natural texture.
* Mechanical Stress:
* Washing, brushing, combing, heat styling, and even sleeping can put physical stress on the hair. This stress can gradually weaken the newly formed disulfide bonds, causing them to break down and the hair to lose its permed shape.
* Exposure to Moisture:
* While permed hair can handle water, frequent exposure to water (especially hot water) can cause the hair shaft to swell and contract. This repeated swelling and contraction can weaken the hair's structure and loosen the curl.
* Harsh Hair Products:
* Using shampoos, conditioners, or styling products that contain harsh sulfates, alcohol, or other drying ingredients can strip the hair of its natural oils and further weaken the permed structure.
* Natural Hair Elasticity:
* Hair has natural elasticity. Over time, it tends to return to its original shape. This is especially true if the permed curls are tightly stretched or pulled frequently.
In summary, perms loosen over time because the chemical bonds that create the new curl pattern are not as strong as the original bonds, and they are constantly subjected to stress from various factors like hair growth, styling, washing, and environmental conditions. The hair's natural tendency to return to its original shape also contributes to the loosening of the perm.