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6-MP Reviews

6-MP Medication
6-MP (Mercaptopurine)

6-MP (also called 6-mercaptopurine or its brand name Purinethol) is a relatively common immunosupressive medication.  Like most ulcerative colitis medications, you need to have a prescription and guidance from your treating physician to use this medication.

People using 6-MP may have a harder time with fighting off infection.

There are many documented side effects (as is the case with many medications) and some of these may include: vomiting, loss of appetite, skin rashes, dark urine.  There is also a chance that 6MP may be toxic to bone marrow. More details about the medication and its possible side effects can be found on wikipedia’s 6MP page – here.

If you have used/use 6-MP to treat your UC, please submit a review on your experience and rating of the medication below.

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6-MP Mercaptopurine
Average rating:  
 47 reviews
 by K
Genetic Testing

I was on 6MP for a few weeks and it made me extremely sick-violent vomiting after taking. It turns out I have a gene that does allow my body to properly process this drug and therefor makes it toxic. Please be sure to get tested for this (TPMT) prior to taking!

 by Teresa
Worked for Daughter

It worked well for daughter for 6 years (along with Lialda). Moved to Entyio to reduce chance of getting cancer due to the length of time she was on 6-MP raising her chance of getting cancer.

 by David
Not for long term

I was on 6MP for a number of years, I'm thinking at least 7 years, or two colonoscopies. I did okay and it kept down the inflammation except for the flare up here and there. The problem is my GI found out that long term use can create a risk of "malignant lymphoma." Other than that, it was just the balsalazide until my last flares which had much more inflammation leading to a Prednisone taper and now Remicade infusion.

 by Mstar123

I started 6MP (50mgs/day)when the asacol stopped being effective in stopping flares and sustaining a health gut. Used it for more than 10 years at 25-50mgs/ day. It takes sometime for the 6MP to kick in but it did help me. Until recently I took the asacol as well at 400/3x/day, and if I did have a flare I used prednisone at 20-30mgs/day for a couple weeks taper. So several actors here, not just 6MP

 by Rod
Worked for awhile

6 MP worked for 6 or 8 months. Then it became ineffective and eventually graduated to remicade. Still have to take 6 MP as a requisite for taking Remicade and it concerns me.

 by mick
Mercaptopurine worked well

I am on mp6, it has kept me in remission for 18 months but my gastro tells I must come off it now because of my age I am 78 and had uc for 19 years. My monthly blood tests were showing results just above border line, I will be sorry to come off it. He says I can try either Methotrexate or Humira as a alternative.

 by Connie Eicher
Mercaptopurine didn't work

Mercaptopurine didn't work, and side effects of fatique and weakness.

 by Virginia Luce
Worked Well

The 6-MP worked well for me for about 4 years. No side effects, blood tests always good except for one time the doc tried to increase and my white blood cell count went way up. That was after taking it for almost the 4 years. Had to go off as it was not working any more.

 by Barbara Rexroat
6-MP No Help

I had severe UC in my entire colon and 6-MP did absolutely nothing so we moved on.

 by Mike

Had to stop immediately because of the sensation of a pincushion turned inside out squeezed with a vise in my midsection. Pancreatitis.

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23 thoughts on “6-MP Reviews”

  1. I’ve been on 6MP for about four months. I have developed liver cysts & will have another ultrasound in 5 months to see if they are stable. I am also on Remicade infusion, Lialda & Rowasa enema. I was in a flare for over a year & now finally in remission with this combination. Not much choices after these if they stop working.

  2. I think 6mp might have been toxic to me. When I was on it, my entire body was stiff and in pain. It made me feel like an arthritic 90 year old with the flu. And even though I kept on complaining, my GI made me stay on it for a couple months until I finally just told him that I was done poisoning myself. Oh, & it really didn’t help with my uc symptoms. Once I stopped taking 6mp, I started feeling less & less like I had one foot in the grave. After about 10 days off it, I was back to my normal ibd symptomatic self.

    1. Amit A

      Btw – did you have the Thiopurine Metabolites test to discover the high liver enzymes and if so how far into treatment were you? I am having similar symptoms and my 6MMP levels after 13 weeks – it is supposed to be under 5700 and I am at 30,000+ .

  3. Been on 6MP for about 6 weeks. Waiting for blood work to see how liver is doing. no problem first t2 weeks. Weeks 3 7 4 felt very nauseous and exhausted. Likened it to my extreme morning sickness I had with my pregnancies. Week 5 has not been as bad. still on prednisone 10 mg. daily. See doctor this week to go over blood work and if I can start tapering off prednisone which I’ve been on again since Dec. ’12. Could not take Lialda. Extremely allergic to it. Chills, bleeding, nausea,headache, ripping apart gut. Afraid to start 6MP after the Lialda reaction.. Thank God this may work. Did think seriously about just going off meds and see what happens. I really felt poisoned by all the unnatural chemicals in my body BUT…who knows what could happen. I’m just diagnosed with UC since dec.’12. I’m still trying to come to terms with the fact that I will always have this condition. It has shaken me up so much emotionally because I am 59 and always been blessed with good health. I should count my blessings, right?

  4. My daughter has used 6mp on and off for two years. The first time it stopped working and they put her on Remicade which may have caused vasculitis in her left eye. She is now legally blind in that eye and will never be able to use the biologic meds like Remicade. She was put on Cytoxan infusions for the vasculitis which also put her colitis in remission. This is a very toxic drug so she could only be on it short term so the colitis came back. They put her back on 6mp but did the metabolic blood tests at Prometheus labs and discovered she needed to be on 300mg. This put her back into remission and allowed her to come off prednisone after two years of use. Now however, her liver counts are too high so they had to drop her to 50mg with allopurinol to help take uric acid out of the liver. She also has severe osteoporosis which is probably from a combination of 6mp, prednisone, and omeprazole. So far she is doing well and we will have her blood tested again to see if her liver counts are down. If not, I am not sure what is next…we kind of ran out of options. All in all…6mp did put her into remission with few side effects but it is very hard on the liver. She is tired all the time and has also had kidney stones but it is always hard to tell what actually comes from medication and what is just from the autoimmune disease itself.

    1. Amit A

      I am very sorry to hear about your daughter.

      How high were her liver counts just before they brought her down to 50 mg of 6MP and allopurinol?

      How often are you taking blood tests to measure the liver enzymes?

      My doctor waited until I had abdominal pain, weight loss, fatigue and an endoscopy before he recommended the Prometheus /TPMT test. Lost a lot of time, weight, blood, and medication money.


  5. I was diagnosed with U.C. at age 21 [approx. 7 years ago] and thought my world was ending as a junior in college. My doctor initially started me on Asacol, but within two weeks I was hospitalized for 5 days due to an rare allergic reaction, which caused pancreatitis. After my allergic reaction, my doctor prescribed prednisone and started me on 6-MP. Within six months I was off the prednisone and taking 75mg of 6-MP daily. I stayed in remission and was able to live a “normal” college life for 3 years without a single flare! No special diet or extreme measures – just 75mg of 6-MP. Since my three years of remission, I’ve had two flares [usually about 1 1/2 years apart] and my daily dosage has gone to 100mg. A month of prednisone ~25mg typically puts me into remission. I’m very fortunate that I do not have any adverse side effects… I’m very active [marathoner, tennis player, & surfer], I sleep fine, & can eat just about anything I want. Every 6-months I have blood work done to make sure my liver enzymes & white blood cell counts are normal. So far so good… The only thing that is now coming into play is the fact that I would like to have children one day, which means I would need to go off the 6-MP for at least six months before trying, which is sure to cause a flare.

    I am a huge fan of 6-MP [on it for almost 7 years now] and would recommend it to anyone who is having a hard time controlling his/her U.C. symptoms; however, it is very IMPORTANT to have regular blood testing while on this drug!

  6. I was diagnosed with UC at about the age of 26. Since then I have been on and off prednisone regiments along with Asacol etc.. You all the know drill! Finally I started 6mp and so far so good, no side effects. I’m a natural worrier so naturally I think about the rare side affects like Lymphoma but I try to tell myself, “what’s the alternative at this point other than surgery?” It’s good to hear that people have responded well to 6mp on here. When you read the FDA warnings it makes you want to stop the drug immediately but as you start reading user stories it helps put my mind at ease.

  7. Amit A

    Wow! I need some help with a decision. This has been a rough journey. I was diagnosed w U.C. in 2009 and on Lialda 4800mg/daily in remission until a Jan 2012 hospitalization/flare which then added Imuran 175mg/daily to the regiment. Coincidentally, shortly thereafter I got sinusitis and was to have surgery but because of the risk with autoimmune meds it would be dangerous. Worked with the GI to try going off of Imuran (staying on Lialda, probiotics, supplements etc…) and the sinusitis cleared up. I decided to stop taking Imuran because of that side effect and by November 2013 flared and ended up in the hospital released with a script for 6MP. 4 week appointment no improvement the doctor said wait until 6 to 8 weeks, 8 week appt. no improvement the doctor said it takes ‘at least 3 months’ then I started getting abdominal pain and reflux. I was given a script for Protoxin which did not work. Went in for a upper GI endoscopy which was ‘visually’ clear and was prescribed Dexilant which did not work. Biopsies were taken. The GI wrote lab orders for a TPMT (liver enzyme test). I called the doctor asking about the pain and reflux and he said up the 6MP from 150mg to 200mg or 33%. I asked him “Doctor, did you look at my blood work since I have been on this for 13 weeks”. He said he had not and would call me back. To my surprise he called back and told me my TPMT/6-MMP levels in Liver were 5 to 6x (30,000) the range of <5,700 and to CEASE taking 6MP immediately and call him in 3 days. No direction on LIVER damage (which I understand is repairable) nor what to do if I flare without my immunomodulator.
    1. Does anyone have experience with what happens after levels reach this drastic of an amount?
    2. How often do those on 6MP get tested OR do you recommend TPMT testing?
    3. Is my next option biologics since I cannot take Imuran nor 6MP?
    Alternatives to biologics? since my doctors have only increased dosage or gone to the next level of medications.
    Any advice on liver toxicity would be great as it applies to U.C. especially and anything I need to be on the look out for as well.
    Adam – this site is a gift. Thanks

    1. Were you still on the immunosuppressants when your sinusitis cleared up? And were you on the immunosuppressants when it started? I’ve been on 6MP and Lialda for 5 years and this past year and a half I’ve been batting a bad case of sinusitis. My ENT never cautioned me regarding sinus surgery because of the immunosuppressants, so I had sinus surgery 7 months ago and am still having sinusitis symptoms. My U.C. is under control but I’m worried the drugs are affecting my recovery from sinus surgery. I’m curious to hear about your U.C. and sinusitis!

  8. Jake S

    Developed pacreatitis within 2 months or less of taking this (Imuran). Had to get weekly bloodwork…not a fun drug. Effective for a while, but side effects pretty substantial.

  9. My son been taking 6 mp for two years , he gets check up every 6 months , this medication has to be monitored very closely !! So far is working but I want to find other alternatives !!! I wish there was a cure for colitis !!!

  10. I was diagnosed with UC back in the mid-90s. I went through the hell like most everyone who has this terrible affliction. I tried just about every remedy. The only thing that gave me relief was prednisone. I was on it, off it, on it, off it, you know the routine. I knew every public restroom within a 25-mile radius of my home. My doctor had been trying to talk me into trying 6-MP for quite a while. I was leery about it since it was a form of oral chemo. Out of desperation, I gave in. That was in late 2001. After a few months of ups and downs, the MP finally settled in. I have been symptom free since. Everything is normal. My blood tests are good. I have been thinking of weaning myself off 6-MP to see if I could go without it. I am afraid to do so. My doctor says yes, indeed, my UC could return if I did. I am wondering if anyone else stopped taking MP after good results such as mine and what the consequences were.

  11. John T. -I’ll respond…though it’s MONTHS later! I was diagnosed with Crohns in my 3rd year of college, when I was in the ER for abdominal pain in April 2010. This all started after eating in the student cafeteria which sent ALL of us to the bathroom. I stopped eating there, but had abd pain which apparently was due to the ileum inflammation. I’m a “mild” case and never had any other symptoms besides abd aches. It was a hard pill to swallow (excuse the pun) with top doctors wanting me to go on 6mp, which I refused and delayed. I took: entocort then Pentasa then 6mp, but in 2012 I was feeling fine and terrified of the side effects, so I stopped everything. For the last year and a half, it’s like I never had anything! Well, the colonoscopy this May saw some inflammation and I suspect they insulted the area with biopsies, causing symptoms to come back. Despite still being mild (thank God and knock on wood!) I do notice new spots of abdominal pain….so yes I believe 6mp or pentasa or whatever did quiet my system even when I was not taking anything, but it can come back….years later, a little bit worse but I’m glad I had that experience…it woke me up to take this seriously. I guess I had to feel it to believe it, even though I suspect a pathogen/bacteria is the root of all this(don’t we all?) good luck!

  12. I just had the exact same experience. 15mg prednisone for 6 months…started 6mp. 8 days into 6mp started waking up with fevers, 101F then 101.5F, then 102.4F. I also had extreme joint pain in my knees. Doc said to stop 6mp. Next morning 98.6F. Still sore knees (first time in my life) but has been going away slowly. Will report more later. Sorry we had to go thru that. Some ppls biochemistry just dont like it.

    1. Update to my last post, turned out the 6-mp reactivated the HSV1 (cold sore) virus in my body and that was what was responsible for my fevers, confusion, and other symptoms. Stopping the 6-mp helped my immune system fight back, but the specialist i saw still put me on valtrex to help with the remaining confusion symptoms. This actually was very dangerous because if my doc hadn’t stopped 6-mp i could have possibly got viral mengingitis due to HSV1 reactivation. Make sure your doctor monitors you for several types of virus reactivations!

  13. I started taking 6mp six days ago. The first three days I coincidently had three good days. The last three days my colitis symptoms are worse than before I started the medicine. Is it a coincidence? My doctor said the medicine would take 2-3 weeks for me to see any potential improvement but my symptoms getting worse isn’t something I expected.

  14. LiLiA

    After a really bad flare in 2013 that put me in hospital for 3 weeks, with IV steroids not working, I was eventually given Infliximab (3 doses). As this drug is only licensed in the UK for emergency cases, my Gastro Dr had to find something else that I could take as a longer term maintenance drug. That’s when I started on Mercaptopurine. The side effects were awful at first. Really bad nausea, loss of appetite and certain foods tasting really strange (I’d have to follow every savoury dish with something sweet, otherwise the taste would stick around for days .especially garlic, onion or spices). I bitterly regretted the day I ate a pickled onion…OMG! I also got lots of infections in the first few months, the worse one was a terrible throat infection that came on so fast that I went straight to casualty as I felt like I couldn’t breathe. My Dr was impressed that I’d persevered for over a month, but with some tweeking, checking bloods regularly etc, my dose was reduced and I was advised to take it at night to avoid the nausea. I’ve been on it now for a year (50mg one day, 25mg the next) and the side effects are pretty much gone. My colitis symptoms have been controlled until 2 weeks ago when the stress of a new job led to some bleeding but that’s all easing now so I’m hopeful it continues to work for me. It is scary taking a chemo drug, but if it works, I’m happy to take it…. for now!

  15. I just started a month ago 50 mg. I stopped bleeding and feel I feel like I am coming out of this flare. But these threads scare me!!!! I feel good but nervous at the same time, this is no way to live but we are stuck with it.

  16. Hi There
    I am looking for advice i have crohns i take 2 grams pentasa grauales daily.I had colonoscopy two months ago inside the sigmoid there was multiple polyps to many to remove lots of inflamation i got a terible fright byopsie came back clear but now daoctor wants me to take 6mp think i might have avascalur necrosis over predisone use .I am affaird to take 6mp over side affects but if i dont im affarid polyps will turn nasty.Advice please thanks.

  17. Have just started on 6mp like most people I have read the side effects but I can’t wait to get some sleep and rest! Prednisone and pentasa can’t get me into remission so I would love to hear some encouraging stories please. Don’t want to have a colectomy but my quality of life is not good

  18. I’ve taken 6 mp for almost 8 years. It took about 3 mos to kick in, as my doctor said it would. We also had to tweak my dose. At first it made me SOOO tired and nauseous. Then we split my 75mg dose – 25 mg AM & 50 mg PM. Made all the dfference, all side effects disappeared. Once it kicked in it kept me in remission almost all of the time, with the occasional mild flare that I treated with Canasa for a few weeks and always went back into remission. Unfortunately, this year over several months 6mp has stopped working. For the past several weeks I’ve been in the worst flare ever. At this very moment my doctor is working to get Humira approved by my insurance and as soon as possible I’ll be starting on that. My doctor told me it’s not unusual for 6 mp to stop working for some people. I hope Humira does the trick, and that any side effects are tolerable. Wish me luck!

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