I don't believe there's any long term research on it. I'd be leery about taking floor cleaner long term, but then, I don't have GERD.

I had issues with GERD until I removed dairy, perhaps there's something in your diet, maybe dairy, maybe some other thing that's still triggering it?

I think it's a little disingenuous to describe d-limonene as "floor cleaner" as one person did. It's a little like describing acetic acid as "window cleaner," sodium bicarbonate as "scouring powder," or dihydrogen monoxide as "solvent." But I digress....

I was going to suggest that, if you haven't done so already, you consider investigating Betaine HCL. This recommendation is based on the theory that GERD symptoms are caused, at least in some people, by too little--not too much--stomach acid. If you have too little, then all those acid reducers might be taking you in the wrong direction. In this case, d-limonene might also be the wrong treatment, as it seems to have an acid reduction effect, according to this:

http://www.ncbi.nlm.nih.gov/pubmed/18072821

However, that link does seem to suggest rather strongly that d-limonene is at least considered safe, non-carcinogenic, non-mutagenic, and non-nephrotoxic. So if it helps you feel better, it probably isn't hurting you too much. Maybe your body is already telling you what you need to know.

I know the HCL suggestion I made sounds completely counter-intuitive, and honestly I was very skeptical myself--until I tried it. I had very good results from a combination of a paleo diet and relatively high doses of Betaine HCL, taken with food. Dairy is not a factor for me, but for some reason, beef sometimes causes me heartburn. (I attribute this to insufficient acid to break it down, causing it to linger too long in my stomach.) But I also have autoimmune thyroid disease, from which hypochlorhydria (low acid) is often a symptom.

I was able to get off PPIs and now have only infrequent episodes. In fact, I now only rarely take the Betaine HCL--it seems my natural stomach acid is returning as other things heal and normalize.

Perhaps you've already tried this, but if not, it might be a relatively harmless experiment.

I'm sorry you've had such a rough case. It can be incredibly frustrating and demoralizing to have the simple act of consuming sustenance result in feeling like crap day after day after day--it's not like you can just stop eating. I wish you good luck, and hope to hear back that you've found some success soon!

In the last five years I started developing vitiligo..the pigment on your skin turning white. My hands, face, arms legs, etc. It freaked me out. I also have reflux and I started taking Jarrow Methyl B 12 complex and Now super enzymes which have HCI and Ox Bile. I take one EVERY time I eat and do you know after a year or so of doing this the vitiligo is almost completely gone! I still have reflux though..Although I'm not sure I would call it reflux, it's more of a feeling of wanting to burp constantly....Try enzymes with ox bile and pepsin and HCI to see if that helps.

This may already be common knowledge, but for acid reflux (and many other reasons) I have found a forkful or two of regular sauerkraut (cabbage, sea salt, and water) can relieve stomach discomfort in a very short time. In addition, sauerkraut is an excellent source of probiotics that can assist in repopulating your digestive tract at a very reasonable cost. I met an older gentleman who is a 7th generation herbalist who told me of the wonders of sauerkraut. One of his most impressive stories was about a client's father who was in hospital and not expected to survive very long from stomach problems. When his son delivered the needed remedy, he was delighted to check him out in perfect health 2 days later. This may not work for everyone, but the investment in a jar of natural sauerkraut - not wine based - for the majority of people I have recommended it to - has been a godsend. There has been a lot of talk about the very expensive and questionable effects of vaccinations against various influenza strains. I have read where those less affluent countries who do cannot afford the big pharma cure, have suggested that their plan is to offer sauerkraut as a remedy. If our immune systems - which includes our digestive tracts - are what keeps us well and alive - my delusion is that we should look to the basics and what is readily available as a good starting point, rather than looking first at the exotic and expensive with potential horrific side effects. However, one size does not fit all - so use your personal discretion