If, as my guess would be, it’s early stage androgenetic alopecia, it’s extremely common hence why I guess your GP prescribed the Minoxidil.
My recollection is that finasteride has decent results (https://doi.org/10.1016/j.jconrel.2019.11.002) too.
Sadly I’m a woman and dont have hair loss so I’ve no direct insight to give you from my own experimentation, but my guess would be to look at your regime of Minoxidil and dermarolling in an extended process. I’d always recommend checking with your doctor, but my approach in your position would be something like:
Division into internal treatment and topical treatment (as youve already done)
Basal nutrition: ensure full B range of vitamins, biotin, l-lysine, d-panthenol and general protein and collagen are present, alongside either Minoxidil or finasteride (are both prescriptions in your location?) and food log for dietary interventions.
Anti-androgenic behaviours such as managing stressors and oxidants in general, and a decent health and sleep regimen, some even recommend visualisation
Topical interventions: you’re already dermarolling so you’ve a pathway to mesotherapy as mentioned below anyway in terms of opening physical channels for substance-delivery.
My memory tells me that Minoxidil’s mechanism of action isnt actually yet proven but is likely to do with the increased nutrient absorption and impact on the hair growth cycle due to its status as a potassium channel opener. The logical question therefore would be which nutrients and substances are beneficial both internally and topically to assist with the hair in its anagen phase when it is actively growing. I’d hope that if you can ensure minimal stressors and oxidants on your body in your hairs catagen phase you may at least see an improvement in the loss, then you can focus on the anagen phase and providing the growth nutrients, maybe through a substrate or carrier gel or oil applied to the area which the micro channels provided by the dermal roller could hasten and improve delivery of.
I hope these are some help at least?
My guess in summary is log your food and supplements, take lots of antioxidants that are plant based even so far as something simple like sage tea to ensure that the stress in the catagen phase is reduced, and derive some breadth of nutrients in a gel (maybe aloe vera based) to apply after dermal rolling that perhaps include amnio acid/peptides such as copper and thymic peptides.
You’ve picked such an interesting challenge because of the hair growth cycle so I’m really looking forward to seeing where you go with this!!!
Some papers which may be of help
Plant derived anti-androgenic compounds
Excellent response to mesotherapy as adjunctive treatment in male androgenetic alopecia by
Daniel Fernandes Melo, Taynara de Mattos Barreto, Glaura Tinoco Plata, Leonardo Rotolo Araujo, Violeta Duarte Tortelly1-s2.0-S0168365919306224-main.pdf (2.4 MB)
Journal of Cosmetic Dermatology 19 (1), 75-77, 2020
https://onlinelibrary.wiley.com/doi/pdf/10.1111/jocd.12983