DEEP MOISTURE
There is a real difference. Dry hair lacks water and responds to humectants and masks. Damaged hair has lost its lipid barrier and leaks what it drinks — that needs protein, oil, or both in the right ratio.
THE SCIENCE
A heavy occlusive for coarse and coily textures. Warm it between palms first, or it sits on top as white flecks.
Penetrates and swells the shaft with water — the most reliable humectant for everyday leave-ins.
Holds many times its weight in water. Best in a water-based leave-in, applied to damp hair before any oil.
One of the few oils that penetrates the cortex rather than sitting on it. Use as a pre-wash on fine hair, sparingly.
THE EDIT
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DO THIS TONIGHT
Layer water first, then leave-in, then oil — in that order, every time.
Deep-condition with heat for 15 minutes, twice a month, not daily.
Swap a daily conditioner for a protein mask every third wash on damaged hair.
Cut heat to the lowest setting that still works.
STRAIGHT ANSWERS
Once a fortnight for normal hair, weekly for bleached or coily textures, and never more than twice a week — over-conditioning makes hair limp and weak.
Water itself is fine; the swelling-and-drying cycle is what stresses it. If you wet daily, use conditioner and skip the blow-dry when you can.