Free medical ebooks on pdf are not rare, you may get them on torrent or over file hosting sites. And yes they disappear fast due to less number of downloads, or the whole file hosting site is down out of sudden. Or you may get a court notice from the publishers and you then have to delete the link. Torrent is best option for sharing medical ebooks but it's not providing best experience.
Here is my list of websites for Medical eBooks (free) (pdf).
Note that not always you can find pdf ebook and here you may find other versions too.
List:
https://smtebooks.com/Category/medical
status : active
files are on: Google drive - often the file is busy with too many visitors.
http://www.ebook777.com/medicine/
status : active but less new uploads
files are on: direct download
https://ebookee.org/medical.html
status : active but less new uploads
files may be lost in many posts.
http://medbookspdf.com/
good for Indian medical students - NEETPG, USMLE notes
http://medbooksvn.net
new url : http://medbooksvn.org/
status : active
files are on: micloudfiles (required adblocker disabling)
http://am-medicine.com
status : active
files are on: nitroflare (often blocked by Indian ISP)
http://freemedworld.com/
Active as of now
files are on Google Drive
http://www.download-books.com
not many medical books
status : active
files are on: userscloud/dailyuploads/filescdn
Apart from these websites, you may find tons of ebooks on Telegram.
To keep these groups safe, I am not sharing them here.
http://www.freebooks4doctors.com/
status: active but not frequent, only free books
hosting: direct url, you may jump into a webpage of full book, mostly no pdf.
**not useful**
http://www.ebook3000.com/Science/Medicine/index.html
status : active
file hosting: required sign up on downloadflix
** old links may not work**
**not recommended**
http://mediprime.blogspot.in
status: seems active
files are on: mega.nz
Down as found on May 20, 2018
http://medicalbooksfree.com/
status : active, less upload, and no recent popular books.
**not useful**
http://bestmedicalbook.blogspot.in/
** old links may not work**
**not useful**
booksmbests.blogspot.in/
status - inactive no new uploads after 2015
expect all links are dead.
**not useful**
http://www.htmedbooks.com
status: DOWN
files may be lost in many posts.
https://www.skudra.net
status :active DOWN
files are on: zippyloads.com
http://ebooks4medical.com
Status:active last update on April '18
DOWN as checked on July '19
File hosting : itiurl and Vk.com / Google drive/ Zippyloads
http://freemedies.blogspot.in
status: inactive since 2015
files may be lost in many posts.
More links to be added....
Here is my list of websites for Medical eBooks (free) (pdf).
Note that not always you can find pdf ebook and here you may find other versions too.
List:
https://smtebooks.com/Category/medical
status : active
files are on: Google drive - often the file is busy with too many visitors.
http://www.ebook777.com/medicine/
status : active but less new uploads
files are on: direct download
https://ebookee.org/medical.html
status : active but less new uploads
files may be lost in many posts.
http://medbookspdf.com/
good for Indian medical students - NEETPG, USMLE notes
http://medbooksvn.net
new url : http://medbooksvn.org/
status : active
files are on: micloudfiles (required adblocker disabling)
http://am-medicine.com
status : active
files are on: nitroflare (often blocked by Indian ISP)
http://freemedworld.com/
Active as of now
files are on Google Drive
http://www.download-books.com
not many medical books
status : active
files are on: userscloud/dailyuploads/filescdn
Apart from these websites, you may find tons of ebooks on Telegram.
To keep these groups safe, I am not sharing them here.
http://www.freebooks4doctors.com/
status: active but not frequent, only free books
hosting: direct url, you may jump into a webpage of full book, mostly no pdf.
**not useful**
http://www.ebook3000.com/Science/Medicine/index.html
status : active
file hosting: required sign up on downloadflix
** old links may not work**
**not recommended**
http://mediprime.blogspot.in
status: seems active
files are on: mega.nz
Down as found on May 20, 2018
http://medicalbooksfree.com/
status : active, less upload, and no recent popular books.
**not useful**
http://bestmedicalbook.blogspot.in/
** old links may not work**
**not useful**
booksmbests.blogspot.in/
status - inactive no new uploads after 2015
expect all links are dead.
**not useful**
http://www.htmedbooks.com
status: DOWN
files may be lost in many posts.
https://www.skudra.net
status :
files are on: zippyloads.com
http://ebooks4medical.com
Status:
DOWN as checked on July '19
File hosting : itiurl and Vk.com / Google drive/ Zippyloads
http://freemedies.blogspot.in
status: inactive since 2015
files may be lost in many posts.
More links to be added....