For topical application, copper peptides for hair growth are available in serums and can be incorporated into a daily scalp care routine
Survey data supports this positioning

A Modern Way to Eat by Anna Jones (Fourth Estate) Serves 810 200g Lancashire cheese 1 egg, beaten, for brushing For the pastry 600g plain flour, plus extra for rolling 1 tsp fine sea salt tsp baking powder A small bunch of fresh thyme, leaves only, very finely chopped 200g butter or vegetable shortening Up to 250ml ice-cold water For the beets 5 medium beetroots, peeled and cut into rough cubes Olive oil A splash of red wine vinegar 2 sprigs of fresh marjoram or oregano, leaves only Sea salt and freshly ground black pepper For the parsnips 4 parsnips, peeled and cut into little fingers A couple of sprigs of fresh sage, leaves picked Zest of 1 unwaxed orange 1 tbsp honey For the sweet potatoes 3 sweet potatoes A little butter or olive oil A good few gratings of fresh nutmeg For the leeks 25g butter or olive oil 2 good-sized leeks, washed, trimmed and sliced 3 sprigs of fresh thyme, leaves picked For the greens 2 heads winter greens, destalked, roughly shredded Grated zest and juice of half an unwaxed lemon 1 red chilli, finely chopped 1 First make the pastry

Ghrelin, the proglucagon-derived peptides and peptide YY in nutrient homeostasis
The World Journal of Men's Health, 37 (1), 45