http://www.hairlosshelp.com/html/nizoral1study.cfm
That study actually shows 1% being slightly MORE effective than 2%.
I seriously doubt there's going to be a huge difference between 1 and 2%. All the studies we have available show them being similarly effective.
That site contains misconstrued information from the actual PubMed study, for some reason it quotes 8.46% increase in hair shaft diameter for 1% Nizoral when that is in fact not the figure quoted in the study:
http://www.ncbi.nlm.nih.gov/pubmed/18498517
"The effect on the mean hair shaft diameter was contrasted between the three groups of volunteers (KTZ: 5.4%, PTO: 7.7%, ZPT: -2.2%)." So that's
5.4% increase for 1% ketoconazole compared to the
7% increase for 2% ketoconazole.
This makes sense, why would a lower concentration be more effective? The only treatment where I can see that being viable is for drugs that follow a hormesis dose response curve like selenium, where too much ceases to cause beneficial effects and too little results in a deficiency. Sites like that pander incorrect information so as to validate the laziness of those in the US who cannot get 2% Nizoral OTC, but is it really that hard to get a prescription or order it online since that's what most people do to acquire finasteride, no?
While this isn't significantly more effective, but is it relevant? Absolutely. The point still stands: why wouldn't you want to use a slightly more effective concentration?
Also I posted this before, I'll post it again:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262531/
" the 1% and 2% dosages of ketoconazole shampoo have hair loss benefits; however, the more potent 2% formulation likely produces better results."
Oh and Paul, thanks for the correction, even still, 2-4x a week of 2% Nizoral usage producing results similar to 1x daily 2% minoxidil usage is impressive nonetheless.