Better than even odds you are a fedposter bringing this stale shit up a year after it was popular...

Don't take doxycycline for influenza or any virus unless you are extremely sick already. It's only good with secondary bacterial infections, and if you are that sick you should find a good doctor.

Take Zinc and Quercetin daily while you have symptoms to inhibit RNA viral replication before you get really sick. This works on all influenza viruses, most cold viruses, and all strains of SARS-CoV-2. Stop taking zinc + quercetin after your symptoms go away. Zinc is not a daily vitamin.

Both are legal OTC. Vitamin D ad K2 are daily vitamins. Everyone should be taking those daily, especially if you are old.

To do it legally, teledoc with a doctor who will prescribe it, then fill it at your local pharmacy.

I use bourbon and honey myself.

Doesn't really help the cold go away any quicker, however.

I learned what glow posting is yesterday. I'd say this fits rather nicely.

Calvetsupply.com

Do you want ugly bluish-black teeth? That's what Doxycycline does to them, I've seen it firsthand and it's gross.

How about you just live through your flu like people have done for thousands of years without intervention? Flu is good for your immune system.