Biotin is also found in many multivitamins which will also include a bunch of other good stuff (like Vitamin D which helps a lot of things, likely including COVID19).
I take this one because gummy vitamins are awesome.
If you get gel or acrylic a lot, take a break. The process of filing down the tops of your nails are....taking off the top layers of your nails.
OR
you are like me and they are just paper thin just because. I started taking a daily women's vitamin (with biotin that's important) and my nails are STRONG and long and healthy. These are the exact ones I buy, just cheap from Walmart. I take two a day and I have seen a noticeable difference in my nails. Even my boyfriend has noticed.
I take these vitamins and use this nail hardener
I use Vitafusion for women. Vitafusion Women's Gummy Vitamins, 150ct, pack of 1 https://www.amazon.com/dp/B007L0DPE0/ref=cm_sw_r_cp_api_glt_fabc_W8E9YC1R83HMMAGEZWG8?_encoding=UTF8&psc=1
Vitafusion Women's Gummy Vitamins, Natural Berry Flavors, 150 Count https://www.amazon.com/dp/B007L0DPE0/ref=cm_sw_r_cp_apa_yUgNybTMNHFDV
Hello! This is the type of Women's Multivitamin that I'm taking now, it's by VitaFusion and was definitely available at my Costco, but here's an amazon link: http://www.amazon.com/gp/product/B007L0DPE0/ref=pd_lpo_sbs_dp_ss_2?pf_rd_p=1944687742&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B00NMFUWHG&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1JANYE2H0EDF1YZX9Z2Y
If you read the ingredients you'll see that two gummies have 100% Biotin, and there's vitamins A, C, E, to improve absorption. I took these Biotin gummies by Nature's Bounty beforehand http://www.drugstore.com/natures-bounty-hair-skin-and-nails-gummies-with-biotin/qxp506347 - and they worked very well for hair & nails, but I'm trying a multivitamin approach so that I don't have to take Vitamin D and B12 separately.
The only thing the VitaFusion is missing in my case is Iron, which I supplement separately.
I recognize that you were asking about collagen - not biotin - but taking the biotin supplements along with regular other vitamins has made a difference for me, so I've just shared what I knew.