Nail strengthener?

[Catinabox21]

Your recommendations for stronger, longer nails please?

Vaseline massaged in at bedtime will see them strong and supple in a week.

Make sure you file gently every day to sharp and to stop ragged edges which may catch and rip the nail.

I've used it every day for well over forty years.

Protein and vitamins

Anything else is just marketing.