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New Study: Pyrithione Zinc shampoo DAILY usage


#1

Therapeutics
The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial
R.S. Berger , J.L. Fu*, K.A. Smiles†, C.B. Turner†, B.M. Schnell†, K.M. Werchowski† and K.M. Lammers†
Hill Top Research, Inc., East Brunswick, NJ, U.S.A. *Reed Hartman Research Center, Cincinnati, OH, U.S.A. †The Procter & Gamble Company, Sharon Woods Technical Center, 11511 Reed Hartman Highway, Cincinnati, OH 45241, U.S.A.
Correspondence to Kenneth A.Smiles. E-mail: smiles.ka@pg.com
Copyright 2003 British Association of Dermatologists
KEYWORDS
male pattern baldness • microscopy • minoxidil • pyrithione zinc • randomized controlled trial
Summary

Background Recent studies of antidandruff shampoos or tonics containing antifungal or antibacterial agents produced effects suggestive of a potential hair growth benefit.

Objectives The purpose of this 6-month, 200-patient, randomized, investigator-blinded, parallel-group clinical study was to assess the hair growth benefits of a 1% pyrithione zinc shampoo. The efficacy of a 1% pyrithione zinc shampoo (used daily), was compared with that of a 5% minoxidil topical solution (applied twice daily), a placebo shampoo and a combination of the 1% pyrithione zinc shampoo and the 5% minoxidil topical solution.

Methods Two hundred healthy men between the ages of 18 and 49 years (inclusive) exhibiting Hamilton–Norwood type III vertex or type IV baldness were enrolled. Total hair counts, the primary efficacy measure, were obtained using fibre-optic microscopy and a computer-assisted, manual hair count method. Secondary measures of efficacy included assessments of hair diameter, as well as patient and investigator global assessments of improvement in hair growth. These were based on photographs of the scalp using both midline and vertex views.

Results Hair count results showed a significant (P < 0·05) net increase in total visible hair counts for the 1% pyrithione zinc shampoo, the 5% minoxidil topical solution, and the combination treatment groups relative to the placebo shampoo after 9 weeks of treatment. The relative increase in hair count for the 1% pyrithione zinc shampoo was slightly less than half that for the minoxidil topical solution and was essentially maintained throughout the 26-week treatment period. No advantage was seen in using both the 5% minoxidil topical solution and the 1% pyrithione zinc shampoo. A small increase in hair diameter was observed for the minoxidil-containing treatment groups at week 17. Assessments of global improvements by the patients and investigator generally showed the benefit of 5% minoxidil. The benefit of the 1% pyrithione zinc shampoo used alone tended (P < 0·1) to be apparent only to the investigator.

Conclusions Hair count results show a modest and sustained improvement in hair growth with daily use of a 1% pyrithione zinc shampoo over a 26-week treatment period.

Dont know what-the-hell to make of that study. If pyrithione zinc helps, then it combined with minoxidil should have even more of an effect…surely they dont both work by the same mechanism. Strange study there.


#2

I’ve read that study before. I’ve also seen posts by a couple of Doctors who allege that Zinc Pyrithione is helpful against MPB because it somehow interferes with the reductase enzymes. How true that is, I’m not sure. However, I’ve also read (though not many seem to be able to post evidence) that Zinc interferes with Minoxidil’s mode of action and can negate its effects. If this IS the case then it might be the reason why there isn’t an added benefit of using a combination treatment of Zinc Pyrithione and Minoxidil together.


#3

» I’ve read that study before. I’ve also seen posts by a couple of Doctors
» who allege that Zinc Pyrithione is helpful against MPB because it somehow
» interferes with the reductase enzymes. How true that is, I’m not sure.
» However, I’ve also read (though not many seem to be able to post evidence)
» that Zinc interferes with Minoxidil’s mode of action and can negate its
» effects. If this IS the case then it might be the reason why there isn’t an
» added benefit of using a combination treatment of Zinc Pyrithione and
» Minoxidil together.

I don’t recall ever seeing a claim that zinc can somehow “interfere” with minoxidil, especially zinc from a shampoo. I find it hard to believe that Rogaine used even right after Head & Shoulders Shampoo would be adversely affected.

Anyway, I just posted a day or two ago in a different thread that Sawaya & Shapiro stated that topical zinc (they different specify what kind of zinc compound they were talking about, or its source) can help not so much by inhibiting 5a-reductase, but by decreasing the production of NADPH, a necessary co-factor for 5a-reductase.


#4

Bryan,

This is what “Doctore’ Lee” says on the subject (via a link provided by Chrome),

"Q. The scientific article in the British Journal of Dermatology also added zinc and pyridoxine to the solution to inhibit 5-alpha reductase. Why didn’t Dr. Lee add them to the Xandrox® solutions?
A. In a 5% concentration, azelaic acid does not need zinc to completely inhibit the synthesis of DHT where applied. Besides, when a zinc salt, azelaic acid and minoxidil are mixed together, there is an eventual precipitate that forms, compromising the desired pharmacological effects of both the minoxidil and the azelaic acid.
Q. So, would you recommend taking the zinc and pyridoxine separately?
A. You can, but there’s no reason to do so. The amount of azelaic acid in the Xandrox® is already sufficient to achieve virtually complete inhibition of 5-alpha reductase and the conversion of testosterone to dihydrotestosterone. Zinc and/or vitamin B6 deficiencies are rare almost everywhere in the world.

Chrome pasted some information from Lee stating that zinc and minoxidil form salts when they are used together, rendering them both ineffective. I have no idea.

Side note: In light of that pubmed study showing that azelaic acid had no effect on sebum, its hard for me to believe that Lee still is pumping it as the mother of all alpha-five inhibitors. You’d think he’d sponsor a test of his own, or at least show some big-time growth pictures on his site or something. That one 1988 study is what he is basing all of that one, never replicated…still (!).


#5

Did find this about zinc and sebum from Belgium:

C. Piérard-Franchimont1, V. Goffin1, G. E. Piérard1 , J. N. Visser2 and H. Jacoby3

(1) Laboratory of Dermometrology, Department of Dermatopathology, University of Liège, CHU du Sart Tilman, B-4000 Liège, Belgium
(2) Yamanouchi Europe, Leiderdorp, The Netherlands
(3) Yamanouchi Pharma, Brussels, Belgium

Received: 31 January 1994 Accepted: 14 November 1994

Abstract In a double-blind randomised study, 14 volunteers applied 4% erythromycin plus 1.2% zinc (Zineryt lotion) and 4% erythromycin lotions, each on half of the forehead twice daily for 3 months. The sebum output was evaluated at 3-week intervals using the photometric and the lipid-sensitive film methods. Evaluations of casual level (CL) and sebum excretion rate (SER) were made with a Sebumeter, and total area of lipid spots (TAS) was measured on Sebutapes. Compared to baseline values, the formulation of the erythromycin-zinc complex induced significant reductions in SER after 6 and 9 weeks, and in CL and TAS at 3, 6, 9 and 12 weeks. The mean reduction in TAS was over 20% for four successive 1-h samplings on completion of the study. Significant reductions in CL, SER and TAS were observed for the erythromycin-zinc formulation compared to the control lotion at 6 and 9 weeks, and also at 3 weeks for SER and TAS, and at 12 weeks for CL and TAS. This study indicates that sebum output is significantly reduced by the erythromycin-zinc complex. This reduction is theoretically beneficial for the acneic patient.

20% doesn’t make my jaw drop or anything though…


#6

Bryan, I merely said that I’ve read some Doctors say that Zinc Pyrithione shampoos interfere with the reductase enzymes. I didn’t say that they block them a la finasteride or dutasteride, just that somehow the synthesis of DHT is inhibited - I didn’t pretend to know by what mechanism this occurs.

Also, on Zinc and Minoxidil, I’ve just read that in a few places. I don’t necessarily believe it’s true or not true, I’m just contributing what I’ve read…I think Sinere may be one the places that held that belief (not sure though, I could be wrong there).

Also, that’s strange that Doctor Lee said that Zinc deficiency is uncommon in all parts of the World. Several sources and nutritionalists I’ve spoken to over the years seem to think that some degree of Zinc deficiency is really quite common!


#7

Dr. Proctor uses Zinc Sulphate in Prox-N and has gone on record by stating that there is ‘good science on topical zinc.’

I also asked him awhile back about the study benji posted and why, if both the shampoo and minox where effective on their own why was there no cummulative effect, and if I recall he said it didn’t mean they cancelled one another out, it just meant that they simply didn’t offer any great advantage over the other when combined, something he often found when experimenting with Proxiphen over the years. (man that was a long sentence!) I also asked him about zinc cancelling out minox and his response was: ‘News to me.’

Anyway, many people have used the topical preparation known as “Zix” which is basically zinc sulphate and B-6 and reported good success, EVEN when combined with Minoxidil, as long as they weren’t mixed in the same solution.

I think if applied seperately, there is no reason why you can’t get the benefits of topical zinc and minoxodil.


#8

It should also be noted that Prox-N was originally designed to be used as an adjunct treatment to topical minox, and according to Dr. P it has always contained zinc sulphate for its SOD properties. Can’t imagine a learned fellow like him would design something as an adjunct treatment to minox that would render the minox ineffective.