A very popular product we used to sell was Lufenuron, used against Candida infection of the mucous membranes. This is our old Lufenuron treatment guide (PDF) when we still sold it for human use (not permitted anymore so we sell the same product for veterinarian use, same amount, same purity).
Derminator before and after photos
Derminator on the scalp for hair growth
Quality issues with dermarollers:
Why we decided to sell our own dermarollers!
Dermaneedling: What do you need to work on your skin issue(s)?
Why we can sell it for $190?
Those Chinese "buzzers" such as Dr. Pen cost around $15 to produce. Their presentation box + shipping costs them more than the actual product. Our machine is very expensive to make, in comparison but we do not pay for fake reviews, ads, YouTube "influencers", affiliates etc. And we do not include a (very expensive!) presentation box. And our machines last forever - so no warranty costs either.
Dr. Pen could easily charge $45 for their product and still make a nice profit. But "cheap" dermaneedling devices raise quality concerns, and the market is prepared, with sufficient marketing hype, to pay much more. So Dr. Pen and the like, all repurposed permanent makeup pens, carry a hefty price tag. Our machine would normally be sold only to clinics, for a price between $2000 and $5000 but our business model, as our website name says is based mainly on serving the home market. So we have a small but healthy profit margin, whereas the Chinese vendors simply make an outrageous amount of money while having no knowledge or care about dermaneedling - their only competencies are marketing and churning out slick-looking garbage.