Methods of using butyric acid derivatives to protect against hair loss

A method of protecting against injury to hair follicles in a subject, comprising:

• administering to the subject an effective amount of a compound having the structure of:
• ##STR8## wherein:
• W.sup.1, W.sup.2 and W.sup.3 each independent from the other represents H, F, Br, Cl or I;
• X.sup.1 and X.sup.2 each independent from the other represents H, F, Br, Cl, I, methyl, CF.sub.3 ;
• Y.sup.1 and Y.sup.2 each independent from the other represents H, F, Br, Cl, I, methyl, CF.sub.3, ethyl or perfluoroethyl;
• Z represents O;
• and
• A represents or Q--CHR.sup.4 --O--C(.dbd.O)R.sup.5 where Q represents a covalent bond or an alkyl;
• R.sup.4 represents H or an alkyl;
• and R.sup.5 represents alkyl or ##STR9## a pharmaceutically acceptable salt or prodrug thereof;
• and wherein said effective amount protects the subject against hair loss.