Help my hair

[isitmeamithedrama]

I need help with my dry brittle hair. It might be age related (42) but I can't be sure.
The sides of my hair, temples to ears, are so brittle they don't really grow because of the breakage.
I feel like I've tried everything
-Vitamins
-Hair oiling
-Weekly conditioning treatments
-hair masks
Cooler showers
Less heat styling

Is there something I can do that will help it grow and look healthier and fuller?

What tests have you had for deficiencies? Anaemia, thyroid, peri, Vit D etc? I'd be checking those before trying yet more things.

What @JC03745 said.

Also, how much/often do you eat animal protein?

I've had thyroid tested-normal on the low side but normal
No iron deficiency
No vit d deficiency

I eat a fairly well balanced diet, I could probably drink more water but big enough to make a diff. I also take multi vitamins alongside collagen supplements.
Dr wasn't interested in the slightest when it was discussed

I've found bond repair very helpful for my hair. Far less breakage, more moisturised, much smoother and no frizz. I've never, ever found anything to tame my hair before bond repair!

Of the cheaper brands I've tried, the L'Oréal Elvive Bond Repair Shampoo & Conditioner is my favourite.

https://www.boots.com/loreal-paris-elvive-bond-repair-shampoo-200ml-10322972

https://www.boots.com/loreal-paris-elvive-bond-repair-conditioner-150ml-10322973

https://www.boots.com/loreal-elvive-bond-repair-bundle-10327823

My least favourite was Pantene. It did nothing for me. But that doesn't mean it's the same for everyone.

https://www.boots.com/pantene-molecular-bond-repair-bundle-shampoo-hair-conditioner-deep-conditioning-treatment-intensive-hair-mask-10342078p

The Hair Lab by Mark Hill Bond Repair Re-Bond Shampoo & conditioner is OK. Not
amazing, not awful.

https://www.boots.com/the-hair-lab-by-mark-hill-bond-repair-re-bond-shampoo-300ml-10297827

https://www.boots.com/the-hair-lab-by-mark-hill-re-bond-conditioner-300ml-10297828

If you've got the money to spend, people rave about Olaplex, but I can't comment on it.

https://uk.olaplex.com/?_gl=11b9o9xx_upMQ.._gs*MQ..&gclid=Cj0KCQiA4-y8BhC3ARIsAHmjC_Ed5WVqZItUGsDNl03J27-QqomdyrPQ8OyjyTv0BGHHRTnVYrxBseQaAtm_EALw_wcB

Redken Acidic Bonding Concentrate shampoo & conditioner might be a good one to try too, but again, I've not tried it. But would be interested to know if its any good.

https://www.boots.com/redken-acidic-bonding-concentrate-shampoo-and-conditioner-bond-repair-bundle-for-damaged-hair-10338063

I have this but im low in iron and vit d.
I'm loving k18 after shower leave in mask at the moment. Also stop permanent dye if you use it, it's very harsh on hair. It ruined mine.