L’Oreal has been researching real solutions for grey hair. Promel (do a search on the Internet), a proposed pill for grey hair, was a complete hoax.
BUT, I came across this interesting post from another site. Looks like L’Oreal is testing a shampoo that actually reverses grey hair. Cool.
It looks like Loreal Paris made some testings according to their newest patent about premature canities.
Patent Number: 20070065389 March 22, 2007
Here is a summary from their patent:
0530] Examples of Compositions TABLE-US-00027 Hair lotion DNA fragment from chromosomal zone included 0.5 g between markers D3S1277 and D3S1285 propylene glycol 20 g 95.degree. ethanol 30 g water qsp 100 g
 This lotion was applied daily to the zones to be treated, preferably to the whole scalp, for at least 10 days and preferably 1 to 2 months.
 A reduction in the appearance of white or gray hairs and re-pigmentation of gray hair was observed. TABLE-US-00028 Treatment shampoo DNA fragment from the chromosomal zone included 1.5 g between the D5S2115 and D5S422 markers polyglyceryl 3-hydroxylarylether 26 g hydroxypropyl cellulose sold as Klucell G by Hercules 2 g preservatives qps 95.degree. ethanol 50 g water qsp 100 g
 This shampoo was used at each wash, leaving it on the hair for about one minute. Long term use, of the order of two months, resulted in progressive re-pigmentation of gray hair. This shampoo could also be used preventatively to retard whitening of the hair. TABLE-US-00029 Treatment gel DNA fragment from the chromosomal zone 0.75 g included between markers D11S898 and D11S925 essential eucalyptus oils 1 g econozole 0.2 g lauryl polyglyceryl 6-cetearyl glycoether 1.9 g preservatives qs carbopol 934P, sold by BF Goodrich Corporation 0.3 g neutralizing agent qs pH 7 water qsp 100 g
 This gel was applied to the zones to be treated twice daily (morning and evening) with a finishing massage. After three months application, repigmentation of hair was observed in the treated zone.