Pumpkin seed oil with regrow some hair. It is also useful for killing parasites. But parasites may not be the reason for your hair loss. There are many reasons.
Also, pumpkin seed oil is just one part of a parasite protocol. I would recommend that you get some FOOD GRADE diatomaceous earth and start taking that. It will replace trace minerals that your body may be lacking and it will also help with parasites. But again, it is only part of a parasite protocol. It does seem to work well on worms, so you might get an indication of whether you have worms or not. Worms are extremely common.
Google Dr. Andreas Kalcker and read his parasite protocol. It's free, it's 18 pages and it will give you a good basic education.
Don't do a lot of herbs until you have a good parasite protocol and knowledge of what you are dealing with. If you start the herbs now, the doctors may blame that for your hair loss.
Clean up your diet, eat organic only. Our foods are heavily contaminated with toxins. Avoid chlorinated water, bromine and fluoride. All will make a bad thyroid worse.

My expertise shows that multi-vitamins in its own generic form doesn't do much. Most of it is excreted. And that's because the forms are the piss poor ones if you follow.

I'll break it down for ya. For vitamins to be effective, they need a chelator. In white people (or black depending on how you see it), we call the vitamin the passenger and a chelator its driver. The vitamin won't do its job or might just not the best way, without the best driver. And what you get from multivitamins is a really crappy driver.

Therefore, I would suggest first doing some research in the best forms of supplements you are looking to take.

Hair loss can be a bunch of different malnutrition states, but before you buy anything (make sure it's not any of the Nature-Made or anything at Walgreens) first look up on Google "Best form of 'insert vitamin name here'" and you should always get a list of the vitamin and possible chelator agents it can be complimented with.

Good luck broski

Infections (stress) increases the need for nutrients since they are being wasted. Biotin is just one of the b vitamins, hair and all cells require the full spectrum of nutrients to do their tasks.

I started taking amino acid supplements and vitamins and many supplements to heal my gut. My hair is starting to get thicker but I dont know if it will ever be how it was.