Should teenagers use sleeping cream?

I don't see why not. It's never too early to nourish your skin. The earlier in life you start, the better your skin will be in the long run. Also, gel moisturizers are friendlier to the skin than cream moisturizers in many cases. I would just verify the ingredients to make sure that the formula is healthy and contains as few harmful ingredients as possible (listed below).

1. ALUMINUM
2. DEA (diethanolamine), MEA (Monoethanolamine), and TEA (triethanolamine)
3. DMDM HYDANTOIN & UREA (Imidazolidinyl)
4. MINERAL OIL
5. PARABENS (Methyl, Butyl, Ethyl, Propyl)
6. PEG (Polyethylene glycol)
7. PHTHALATES
8. PROPYLENE GLYCOL (PG) & BUTYLENE GLYCOL
9. SILOXANES
10. SODIUM LAURYL SULFATE (SLS) & SODIUM LAURETH SULFATE (SLES)
11. SYNTHETIC FRAGRANCES
12. TRICLOSAN

I do think teenagers must stay away from creams or much skin care because later in 20s and 30s , have to use creams anyway.