and:
http://www.patentstorm.us/patents/6270752/description.html
“A 5 alpha -reductase inhibitor according to the invention comprises d-limonene, which has an excellent activity inhibitory effect and is highly safe without any drawback as noted by side effects and thus is a suitable component for a hair grower”
…from the second patent:
"The trichograms of tested subjects randomly divided into 10 groups, were performed in order to evaluate the effect of the formulations on the hair loss inhibition at the beginning and at the end (90 days) of the treatment. The trichogram consists in the withdrawal of a suitable number (about 50) of hairs using rubberized forceps, from the superior-frontal and latero-nuchal areas.
The microscopic examination of hair roots allows to evaluate the hair quantity which is in the anagen (growth), catagen (mature) and telogen (rest) phase. The reduction in the anagen percentage and the increase in the telogen percentage, with respect to normal values (which are about 85-90% and 10-15%, respectively), represent the clinical evidence of a pathological hair loss.
TABLE III Trichogrammic effects induced by the topical application (90 days) of the lotion prepared according to the example I Trichogram (% - m ± e.s.) Treatment telogen anagen + catagen Alc. dist. Before 76 ± 3 24 ± 1 After 90 days 81 ± 3 19 ± 1 Alc. dist. + Before 78 ± 2 22 ± 1 Salic. Ac. After 90 days 82 ± 2 18 ± 1 Ac. + dist. Before 74 ± 2 26 ± 2 Ac. salic. + After 90 days 86 ± 3* 14 ± 1* Fats *= p < 0.01 vs basal as the result of the calculation."
Me again…I looked around for what contains “Limonene”, and it turns out that there are quite a bit of hairloss-oriented or “thickening” shampoos that do indeed have this stuff, as well as some citrus oils that you find in shampoos.
Contains limonene: Alpecin shampoo and after-shampoo liquid, L’Oreal “Thickening” shampoo, and in fact just about every L’Oreal shampoo I looked at.
Citrus oils extremely high in limonene (that are oft-in shome shampoos):
Orange oil-----is about 90% limonene
Grapefruit peel oil------over 70% limonene
Lemon and Lime oil-------a great deal of limonene, over half the oil in fact.
Rosemary has about 2.5% limonene
Sage has some limonene
Peppermint oil has some limonene (quite a bit if I remember correctly)
Eucalyptus has a good bit of limonene
Lavender has some limonene
Lemongrass has some limonene
Head and Shoulders Pyrithione Zinc shampoo has grapefruit oil (mostly limonene) in it.
Garnier Fructis “Strengthening” shampoo has lemon peel extract in it. There would be a lot of limonene in that.
American Crew “Citrus Mint” shampoo has a couple of different citrus oils in it.
I think that “Fuller Thicker Hair” shampoo has one of the citrus oils in it (might be grapefruit).
Ive seen a few shampoos with lemongrass in them, but they use the long-name (cycobolm-something-or-other)for the lemongrass.
Why I bother with this kinda thing…I have a very itching feeling that cosmetics companies do a great deal of testing that we never hear about because its private. We know L’Oreal for instance and Redken have hairloss products sold in Europe (Redken uses Hops for an alpha five reductase inhibitor sold in some kind of patch worn on the back). Its very likely they have found successful inhibitors of alpha five reductase, but are barred from outright stating that by the FDA, and dont want to arouse “side effect” fears (which are legitimate if you talk to enough people who have used tea tree oil shampoos…topicals can indeed go systemic, especially oils with small molecules). One of the patents mentioned two “positive controls” tested on rats with the limonene and they were glyzheric-something-or-other (which means licorice), and something called “Duke extract”, so we can add that to hops as entities that these companies at least have tested and believe somewhat effective 5AR inhibitors.
I have no idea if these oils penetrate well or whatever, but getting pure D-limonene in a shampoo (L’Oreal and Alpecin) is available and might be a decent over-the-counter addition to Nizoral. I picked up a bottle of the L’Oreal Thickening Shampoo for men and used it…and its pretty nice stuff.