My hairline is moving back from the corners. is there something i can use to prevent it getting worse?

Your options: Hair loss at temples, without other thinning areas, can be final adult hairline sculpting. Usually completed by 30, thisis not male pattern baldness (mpb). If you're over 30 with significant thinning at other spots, this is likely mpb. Some data suggest vitamin d (d3 3000 iu/day) can help. Only proven treatments are topical Minoxidil and oral finasteride. Beware of the many scam remedies sold.