My experience: My hairs is fine. Vegan 15 years almost. Partially raw all this time. Went thru thin hair phase in Malaysia 7 years ago. Attribute this to detox and climate change.. sweating a lot also then.
My hair is now the longest its been in long time and my beard.
I suggest try ho shou wu.
Also bending over and head massage is very important. Especially massage. Dry finger massage. Can't be easier and finger wet massage when showering also.
Get circulation to your follicles.
Also quit all chemicals for shampoo and personal care from ordinary stores and buy natural cosmetics of all kinds. What you put on skin gets absorbed and chemical things like deodorant, after shave, shampoo and conditioner, and household cleaners not from the health store or homemade help cause illness and disease.
For cosmetics try either health store stuff or what i use is baking soda and apple cider vinger for hair cleaning and conditioning alike. Usually just water except clean head and hair maybe once every 7-9 days.
I use nothing for deodorant for 10 years or more and don't need to as I eat cleanly.
For hair and body I use organic coconut oil usually, sometimes organic olive oil but thst can be thick and cuase spots on skin if used too much.