health effects

Difficult to say, really. There are possible psychological benefits in achieving such orgasms, for a start.

I don't think any serious medical study has been made and it would be unwise in the current litigious climate for the manufacturer to make any particular medical claims.

kevinday,

Please read Aneros History from the WIKI for some background here. Most of the evidence touting prostate massage is anecdotal, however, High Island Health LLC is a participant in an ongoing clinical study of the benefits of prostate massage for symptomatic relief of pain from BPH and chronic prostatitis.
FYI, High Island Health LLC is the parent company & manufacturer of the Aneros ® brand of prostate massagers. This patented device was originally and is currently offered for sale as the Pro-State ® line of massagers on the High Island Health website. The HIH website is primarily oriented toward the health aspects and benefits of prostate massage in accord with Oriental medicine for prostate related issues. A forum for users to discuss practice with these devices also exists on that website, I encourage you to check out that site to learn more about the health benefits. You may also be interested in reading about the ongoing Columbia Medical School study using the Pro-State massagers. The High Island Health website also contains testimonials from users regarding their experiences using these wonderful little massagers. The Aneros® website, by contrast, is oriented toward the sensual pleasure aspects of prostate massage.
Good Vibes to You !

I think benefits may vary from person to person, but personally I've found that after 1 month, I've seen the following benefits.

1) Relaxation and less muscle tension following a session
2) Decreased hemmeroids
3) Firmer (more frequent) erection, better ejaculation control, and more sensation during sexual activity. I've also noticed increased PC muscle strength and control (which is why I bought it in the first place)
4) Less nightime urination and more complete emptying.

I read this recently http://articles.latimes.com/2013/may/08/science/la-sci-sleep-disruption-cancer-risk-20130507 , and while may people have noted that they don't sleep well with the aneros, I've noticed the opposite. I sleep very well after a strong session, and many times have fallen asleep with it in during deep states of relaxation. I found the hypothesis of this article to be intriguing. Science still does not clearly understand all there is to know, and I'm wondering if my previous sleep disruption caused by restless legs syndrome and muscle tension aren't related to my prostate, and somehow massage before betime released endorphins or otherwise flushes my system of compounds which may be causing sleep disruption.

On the downside, all of the benefits I've gotten have basically made me an addict, where I can't wait to find time to have a session. A month ago, the best PC flex I could do was tighten ing my anus for about 2 seconds... now I can actually control the different muscles group, and do light or hard contractions. Wasn't able to do that flexing alone... aneros allowed me to learn how to use those muscles.