Unisex hip protectors are designed as a one-size-fits-most compromise, but that compromise matters more than you might think. The critical issue is pad placement—hip protectors only work if the padding sits directly over the greater trochanter (the bony point on the side of your hip). Because men and women have different hip widths and pelvic structures, a unisex design may position the pads too close together for women or too far apart for some men.
For women especially, unisex models are risky. Wider female hips mean the pads often sit inward of where they need to be, leaving the actual impact zone exposed. A women's-specific model is strongly worth seeking out if that's your situation.
Unisex protectors can work reasonably well for men with average builds, and they're a practical choice for shared family gear or rental programs. Just know that you're trading some precision in protection for convenience—and with hip injuries, that precision really counts.