A list from eBizMBA was just posted regarding the Top 15 Most Popular Health Websites as of March 2015. The eBizMBA top health website lists have been posted in healthsprocket a number of times in the past. It's interesting to compare current rankings with a couple of past data points, so here goes - here is the current top 15, with their corresponding rankings from May 2014 and May 2011 indicated:

eBizMBA Top 15 Most Popular Health Websites

WebMD Rank.......... 3/15 1st | 5/14 1st | 5/11 3rd | Unique Visitors (million): 3/15 80.0 | 5/11 19.5
NIH...................... .3/15 2nd | 5/14 2nd | 5/11 2nd | Unique Visitors (million): 3/15 55.0 | 5/11 20.0
Yahoo! Health.........3/15 3rd | 5/14 3rd | 5/11 1st | Unique Visitors (million): 3/15 50.5 | 5/11 21.5
Mayo Clinic............ 3/15 4th | 5/14 4th | 5/11 5th | Unique Visitors (million): 3/15 30.0 | 5/11 7.0
MedicineNet............3/15 5th | 5/14 5th | 5/11 3rd | Unique Visitors (million): 3/15 25.5 | 5/11 19.5
Drugs.com............. 3/15 6th | 5/14 6th | 5/11 6th | Unique Visitors (million): 3/15 22.0 | 5/11 6.0
EverydayHealth...... 3/15 7th | 5/14 8th | 5/11 7th | Unique Visitors (million): 3/15 18.0 | 5/11 5.7
HealthGrades......... 3/15 8th | 5/14 7th | 5/11 10th | Unique Visitors (million): 3/15 17.0 | 5/11 4.2
Healthline.............. 3/15 9th | 5/14 12th | 5/11 15th | Unique Visitors (million): 3/15 16.0 | 5/11 1.9
Mercola................. 3/15 10th | 5/14 9th | 5/11 ---- | Unique Visitors (million): 3/15 15.5 | 5/11 --
Health.com............ 3/15 11th | 5/14 10th | 5/11 ---- | Unique Visitors (million): 3/15 15.0 | 5/11 --
MindBodyGreen.......3/15 12th | 5/14 13th | 5/11 ---- | Unique Visitors (million): 3/15 10.5 | 5/11 --
Medscape...............3/15 13th | 5/14 ---- | 5/11 ---- | Unique Visitors (million): 3/15 9.0 | 5/11 --
RxList................... 3/15 14th | 5/14 15th | 5/11 13th | Unique Visitors (million): 3/15 7.0 | 5/11 1.9
MedicalNewsToday: 3/15 15th | 5/14 14th | 5/11 ---- | Unique Visitors (million): 3/15 6.5 | 5/11 --