The FDA maintains that all generic drugs are “identical” to their brand name counterparts. Of course, the word identical does not mean the same thing to everyone. Most of us assume that identical means exactly the same. For example, identical twins have the same exact DNA. If you drop your iPhone down the toilet and want to replace it with an “identical” iPhone, you can be confident that your new iPhone is exactly the same as the old one.
The FDA, however, has a different definition for identical, especially when it refers to generic drugs: “A generic drug is identical–or bioequivalent–to a brand name drug in dosage form, safety, strength, route of administration, quality, performance characteristics and intended use.”
What the FDA does not tell you in this sentence is that generic drugs can have different “inert” ingredients or fillers. In other words, all the other stuff except the active ingredient could be completely different. What’s more, the formulation can be be quite different. Take Wellbutrin XL 300, for example. This brand name antidepressant gradually releases the active ingredient bupropion over the course of a day. It uses a “membrane” technology for this slow release.
One generic equivalent, Budeprion XL 300, uses a “matrix” technology for its slow release. The same amount of bupropion (300 mg) is released, but the timing is quite different. Budeprion XL dissolves and releases its ingredient more quickly. The FDA confirms this in a report it has released on its Web site.
We have received hundreds of complaints about Budeprion XL 300 not behaving like the brand name Wellbutrin XL 300. In an unprecedented response to these concerns, the FDA and the manufacturer and distributor of Budeprion are planning a study. Perhaps we will learn if the two formulations are indeed “identical” or not. It will take time, however, to collect and analyze the data.
Budeprion XL 300 is not the only generic drug raising questions. Over the last several years we have received hundreds and hundreds of complaints about a variety of generic drugs. They range from the generic form of the anti-seizure drug Keppra (levetiracetam) to the heart drug Toprol XL (metoprolol succinate), the heartburn medicine Prilosec (omeprazole) and the pain reliever OxyContin (oxycodone).
If you would like to report a problem with a generic drug, either side effects or lack of effectiveness, please add your comment below. Put the brand or generic drug name at the top of your comment. We will forward your story to the FDA.

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  1. Lawrence
    Newport RI

    Was taking 20.6mg Prilosec for two months which gave complete relief of my acid related stomach pain. It was the first time in years I had felt this good. Then BCBSRI refused to pay for it and I was switched to the generic omeprazole and within 3 days the pain is back. Neither my PCP nor gastro doc believe me. I’ve tried everything else possible in OTC and nothing works. I’m appealing the insurance company but I don’t have much hope. The relief was certainly nice while it lasted.

  2. Stacye R.


    After I was diagnosed with acid reflux my doctor prescribed Nexium DR 40mg for treatment. I’ve had good success with this medication if taken every day and not skipping a dose.
    Recently it was time for a refill, to which I picked up my medication, get it home only to find out that Lil “purple” capsule is now “blue” with a sticker on bottle by pharmacist stating “this medication is the same but may be a different color, size or shape.
    I have had more acid reflux since starting on this bottle than I have had in years! There is no way it is the exact/identical to its brand name NEXIUM! I do want to add, I do not have a problem with generic drugs if they perform the same as the brand but when my Acid Reflux wakes me during night from a night of resting, I definitely have a problem!

  3. Jerry
    Las Vegas

    For years I took Dilantin 100mg capsules.

    Some time ago my doctor okayed the generic equivalent which is produced by Bertek (White/Lavender capsules). Those worked excellently. and, as far as test results show, identically.

    Then, I had to switch pharmacies and they, also, dispensed the Bertek version.

    Lately, the same pharmacy uses the Bertek product and at other times dispenses capsules produced by Taro (orange).

    My former physician once made the comment that he’d never seen anyone with more consistent phenytoin levels than those indicated on my labs.

    Lately (using the Taro branded capsules) my new doctor was mildly concerned that my tests indicated elevated phenytoin levels.

    Are the Bertek and Taro products REALLY identical ? Have you had questions re: this matter before?

  4. Angela
    New York

    I have been taking Levetiracetam ER 2000mg at bedtime by Sun PHARMA, without any problems, my pharmacy filled my RX from another company since they were out of stock, needless to say I had a seizure. Now my daughter is on the same medication 1500 mg. I have just been informed by cvs they will no longer be able to get my medication from sun PHARMA anymore. I am quite concerned and do not know what to do. Do different pharmaceutical company’s meds have different ingredients in them? Any information would be helpful.

  5. Catherine M C
    United States

    I had been on brand-name Plavix since 1999. In June 2013, I was switched to the generic Clopidogrel, manufactured by Aurobindo in India. I am no longer feeling normal in my stomach. Burp, burp, burp. Regurg occasionally. Throwing up. And food doesn’t taste good (lobster? prime rib?). My stomach distress became slowly worse over a six month period. By Thanksgiving I could not eat more than a couple of bites of food at a time, and I had lost 8 lbs.

    At my December 2013 blood test, I watched the blood go into the tubes and it was thicker than it has been for the last 14 years. Also, no bruise leftover at the puncture site. In fact, no bruises anywhere on me at all which is not what I grew to accept as “Plavix-normal”.

    Also, two knife cuts in the kitchen during holiday food-prep produced no bleeding at all. By January, I suspected the Clopidogrel was only not working as a blood-thinner, but was poisoning my gastro tract.

    In January 2014, I requested my Doctor write a DAW for the brand name, which I had to pay for entirely ($220/30 days). Within one day of stopping the generic, my stomach started feeling a tiny bit better. Over the next 6 months, I slowly returned to normal. I have had problems in the past with other generics not working at all, but I never before had one make me physically ill. I complained to my pharmacy, but they deny receiving any similar feedback. My doctor recorded that I need the brand name going forward. However, I think I am not alone in wishing to be grandfathered on long-use brand name products, especially considering the other complaints I am seeing. And the FDA should know about this!

  6. bonnie

    PMS Oxycodone 80mg (Pharmascience- generic)
    My usual monthly refill from Apotex OcycodoneCR80 mg, unfortunatly could not be filled, the first week of January 2015, as my pharmacy is out of stock, as well as Apotex warehouse. So, I had to be substituted with the Pharmascience Oxycodone 80 mg. I have to ask if this generic actually has Oxycodone in the ingredients?
    This is the absolute worst generic I have ever taken! My dosage is( 2) – 80 mg every 6 hours. I have taken this substitute now for 8 days, I am in terrible pain. I am experiencing pain I have never felt before. Today I took 4 in a 4 hour span.
    This has to be a joke, I am still suffering in pain at that dosage. This is ridiculous!
    I would love to be able to test this product on how much pain relief oxycodone levels there actually are, I would think barely detectable.
    A patients daily quality of life depends on this medication. My days since the substitute have been cut in half, as I cannot do what I usually am able to do with taking the Apotex. My day is now ending at 3:00 pm having to lay down, to help my pain. Very frustrating! Now waiting patiently until my pharmacy does receive out of stock generics, again another question is why is this happening? out of stocks- should not be acceptable- whose fault is this ? I had to write in as to state there are differences between generics, my experience so far is a huge one!
    Not happy with my substitute!

  7. jim t.
    United States

    There are definitely differences between the products Generic producers sell.
    I have had to use two 40 mg capsules of Omeprazole for 25 years. I tried many different generic producers product but experienced side effects (diarrhea) on all but the Mylan Labs or Prilosec.
    Now that I have reached Medicare age and obtained a Drug plan. My original plan used Walmart pharmacy which when I signed up, used only Mylan for their product. Some months ago they went to others, probably for their cost. I have to special order the Mylan product since I am being provided product from other producers.
    What a pain!

  8. Ron W.
    St Louis Missouri

    I began taking (Par Pharm) Bupropion 300 xl A102

    My blood pressure has skyrocketed to the danger levels had to stop a medication that was doing me so good. I am very frustrated and mad.
    My insurance will not cover Brand name Wellbutrin 300 XL.


  9. petrarca

    Omprazole 20 mg generic version, pill has a creamy colour and it says OME 20……..won’t work as the original for me, I tried it and I can guarantee that.

  10. Tracy

    I have been switched to Percocet from hydrocodone. My Percocet came generic from Actavis and it does not work at all for my pain….the reason I had to stop the hydrocodone! I paid a lot of money for this generic med that gives no pain relief but does give stomach cramps, nausea, headaches, increased anxiety and constipation I have never experienced the likes of before! I called Actavis and, besides my name, address, and state I live in, they didn’t care what I had to say! These inferior generic meds have to stop making their way to our pharmacies …..not just narcotics but all of them, and quit sending us on a road to hell with no end in sight! I have to deal with this for at least 3 more weeks and then what? Try another generic that might work? I am seriously thinking about giving up taking any meds and just try to live. I won’t be able to do anything but I can’t stand this pain and misery anymore either! Aren’t chronic pain patients worthy of a life???

    • bonnie

      Your comment I believe is felt by many chronic pain patients across the country!
      There is a huge difference between generics, and huge difference between brand name and generic!
      C’mon, Pharmaceutical companies, this is a no brainer!

  11. M.D.H

    I was taking Singular 10MG for my allergies and it worked really well, then I was switched to the generic Claritin which ironically I found that I’m allergic too. After that I was switched to Montelukast 10Mg ML 1 and it didn’t affect me whatsoever, then I was switched most recently to another Montelukast 10mg 54 157 and it doesn’t work that well. Also I was taking Nexium 40mg and it worked great, then they switched me to the generic Omeprazole 40MG and it didn’t work that often, then very recently I was switched to Pantoprazole 40mg. Though, I haven’t had it very long to see how it affects me yet.

  12. RC

    I’ve been taking Phentoyin Sodium (generic Dilantin) to control a seizure condition for over a decade with no problems. The last time I filled my prescription at Walgreens l was informed that they had switched generics (pretty obvious since the new pills are orange).
    Besides the pills tasting like crap, I have had several petit mal seizures. They are minor, but can happen several times a day. Fortunately I’m just about ready for a refill. I will be going into Walgreens tomorrow and demanding that they fill my prescription with name brand Dilantin, but only charge me for the generic. Failure to do so will result in a lawsuit.

  13. RC

    I’ve been taking Phentoyin Sodium (generic Dilantin) to control a seizure condition for over a decade with no problems. The last time I filled my prescription at Walgreens l was informed that they had switched generics (pretty obvious since the new pills are orange). Besides the pills tasting like crap, I have had several petit mal seizures. They are minor, but can happen several times a day. Fortunately I’m just about ready for a refill. I will be going into Walgreens tomorrow and demanding that they fill my prescription with name brand Dilantin, but only charge me for the generic. Failure to do so will result in a lawsuit.

  14. MLL

    I have been taking synthroid for 20 years. My doctor has always had me on the brand name until my script was renewed and they forgot to check the do not substitute box. I didn’t think anything of it and started on the levothyroxine and about 5 days in I started get heart palpitations. I called my doctor and told him what was happening and he called in a new script to my mail order pharmacy and a supply to my local pharmacy so I could go back to the synthroid right away.
    About two weeks after switching back to the non-generic the palpitations stopped. I didn’t think much about it until about 3 years ago when my doctor started me on a statin. The script was filled with the generic version, again about four days in I started getting palpitations, only this time they were severe. My doctor took me off the statin and referred me to a cardiologist for the palpitations. About two weeks off the generic statin the palpitations eased up, however it took about three months for them to stop completely.
    I have had every heart test under the sun and everything has come back normal. About two weeks ago I was having bad chest pains and went to the er, they did all of the test, nothing, other than my blood pressure was very elevated. I followed up with the cardiologist and was put on Atenolol. Again, didn’t think anything of it until about four days into taking it. The heart palpitations have started up again. My PCP has called in the non-generic version of Atenolol and wants me to follow up with the cardiologist. She is not convinced that it is the generics causing the palpitations but since they seem to go away when I stop them, I think they are the cause.

  15. Michele


  16. skrobbins

    My drug plan just switched to mandatory generic, but I was already taking a generic for percocet, oxycocet. I was told by pharmacy no longer stocking this brand. I had tied taking endocet before and found it ineffective. I was give sandoz brand 325:5 but I asked for only one week. I found myself nauseated and dizzy after each dose. I mixed tablets and asked by husband to give them as a blind test. Each time I took the sandoz I became nauseated and dizzy. ALL GENERICS ARE NOT THE SAME!!
    When I looked up on web I was told the dose could vary from 7- 12% as opposed to 10% composition purity in percocet. their answer increase the dosage!! I have a deteriorating disc and this has been my treatment for 10 years with effectiveness and no need to ever increase. And now I am to increase because there is a flaw in the generic drug!!! I will be fighting the insistence for generic drugs and quite honestly my experience makes me want to insist on NO more generic drugs.

  17. EG

    Bupropion XR 150, Mylan brand
    (Generic Wellbutrin XR)
    Since going off of the name brand Wellbutrin XR tablets, I noticed immediately that I was feeling sluggish and unmotivated during the day. It was definitely not doing what it was supposed to do. I have not since switched back to the name brand, because my insurance company will not cover it now that it has gone generic. I’m really hoping someone is going to start looking at the efficacy of these generic drugs because I can’t effectively treat my illness with constant inconsistency in my medications.

  18. EG

    Quetiapine, Pharma Science (Pms) brand 100mg tabs
    (generic seroquel)
    Bipolar disorder
    I have used quetiapine in various forms for years, including the name brand medications and several forms of generic brands. I have never had an issue with efficacy before my recent switch to the PMS, or Pharma Science brand, generic tablets.
    The results of quetiapine have always been predictable, right down to how much I had eaten that day and how tired I was feeling in general. Usually about an hour after taking the tablet, my nose would suddenly get stuffy, and shortly after I would begin to feel sleepy and know that it was time for bed.
    Since starting the Pms brand, the effects have been unpredictable and frightening. I could go for days with it seemingly doing nothing – no stuffy nose, mild sleepiness and generally didn’t seem to be working, with mood easily irritated. Then, out of the blue, a tablet would make me feel as though I had been knocked over, very low blood pressure and weak heart, generally feeling horrible and barely make it to bed. I have stopped taking it and I’m returning it to the pharmacy today to exchange it with Novo brand, which has never failed to work consistently.

    • bonnie

      PMS has to be the worst generics out there!
      Every generic they make is being talked about as ineffective- thought I was the only one.
      Cannot this company be investigated? when patients are willing to make valid claims about their medications. We don’t want money we just want to be able to live a daily normal life with our conditions.

      Unfortunately as a customer pharmacies do not allow exchanges, ever.
      New prescription is needed.

  19. EM

    I have been taking generic omeprazole for years for acid reflux. It has worked well for me. Then I got on a new insurance plan and was forced to buy through Xpress Scripts mail order for all my standing prescriptions. A the 2nd day of the new generic, I started to feel a little acidic. By day 5, I could feel the burning in the back of my throat even while standing.
    Now, I actually have mini regurgitation events by the end of the day that are so acidic they burn like mad – and I am back to having the mid-chest and back pains that make me feel like I have an arrow through my mid-section.
    I guess I will go buy over the counter brand name pills at a substantially higher cost and take 2 to get to my prescribed strength as I have no other choice with my prescription coverage.
    I am extremely disappointed in the FDA for not stepping in to ensure mail order prescriptions are what they say they are. I am obviously getting a placebo worth nothing to me whatsoever. I am angry and not really in a position to afford this.
    I am in double jeopardy as I also have to get my gabapentin through this mail order place. I use it to control chronic sciatica from an accident I was in 30 years ago. I can already feel the bottom of my foot start to ache. The only problem is, there is no over the counter solution for this. I am basically just screwed.

  20. MG

    Amlopidipine-Benazapril 5-10 generic for Lotrel made by Watson labs and purchased at Costco pharmacy is totally ineffective. My husbands BP went up to untreated numbers on this drug. I did report this to the FDA already and to the pharmacy.

  21. JN

    I have tried both Paxil CR 12.5 mg and Prozac in their generic forms at different times. Neither one of them worked for me but as soon as I switched back to the name brand I was feeling better. Both times I didn’t even know they had switched my pills to generic I thought they were just made from a different manufacturer until I started to not feel as well so I checked into it and found out they were both generics. I wish we could buy the Name Brand for cheaper than it is.
    Jill N.

  22. DW

    I have been on Wellbutrin XL 300 mg for quite a few years now. I never knew there was a correlation between my mood swings & the unease I felt when switched from the Wellbutrin to Watson Bupropion. Its like I am not even taking them. Also I have noticed that the pill does not dissolve. I find the pills, same size & shape in my bowel movements, I notice this because I also have very loose stools. I do not know if this is another result of the Watson generic or not. I doubt my Doctor will believe me about this. Because I am an older female (60 years old) he has started thinking I am either making medical problems up or just spending my money to see him tell me nothing is wrong. What should I do and how can I make him believe me?

  23. Amanda

    I agree with you. I have been on oxycodone 10mg for almost two years and it has worked really well. I have been able to get my life back. I got my medicine this month and it was from zydus it is terrible. It does not work and it has made me sick to my stomach and I have this weird salt like taste in my mouth that I can’t get rid of.
    I called the pharmacy and they talked to me like I was stupid. I am already having a problem finding a pharmacy to fill my meds anyway cause my doctor is out of town and now this. I don’t know what to do and think this is so wrong. Since when did we give the government power to tell us where we can go to the doctor at and what brand of medication we get just because it is a narcotic.

  24. vem

    Topomax – zydus topiramate
    I was taking a generic from another company (I don’t know which one.) I was recently switched to the zydus generic. It was like I had been anesthetized. I could not sit down for more than 10 minutes without falling asleep – and not for a few minutes – for an hour or more. My entire body felt numb. I could have probably slept for 18 hours a day if I would have let myself. I quit taking the drug and I was fine.

  25. JS

    This may be too late but I changed from Fosamax to Boniva because my physician felt that I had been on Fos. longer than I should. Everything was fine and I loved it because it was once monthly. Then along came the insurance company and my employer. In order to reduce cost I went to the generic Ibandronate (monthly) It seems to work. Just something to discuss with your doctor.

  26. Steve - Dallas

    That was NOT the end of it. My pharmacy went back to dispensing Warner metoprolol, despite my protests. After a couple of months on Warner, I was experiencing an irregular heartbeat all the time. I did a search of other pharmacies in the area, and found that CVS was dispensing PAR. So I’m getting my metoprolol there, and hope they don’t decide to switch, too. I don’t want to have to pay the “out of pocket” price for Toprol.

  27. Christopher D.

    Have had anxiety issues since starting to take Zydus generic oyxcodone (10mg), been on pain meds for about 2 years now due to back pain and 2 operations to fix, never had this issue before, believe it could be possibly in the fillers that they use. Has anyone else found this to be true?

  28. SM

    metoprolol succinate–I only do well on toprol XL and battling my insurance company for approval–haven’t gotten it so far even though the DR has called and said I get break through A FIB on the generic (my heart rate gets too high). They say the drug is identical–well my symptoms on it aren’t identical. Wake up people. We aren’t making these symptoms up.
    Also I don’t do well on Omeprozole–I just pay more now and get prilosec over the counter. reflux came right back with omerprozole.
    I hate being at the mercy of insurance companies who determine if we can get relief or not. I sure can’t afford Toprol XL on my own.

  29. Gale G

    My doctor got the insurance to approve the brand name Zyprexa for the reminder of the year. I can tell the difference already and it has been only about 10 days.

  30. TS

    I have the same problem with generic Wellbutrin and I think it’s terrible that so many people have to go through this. We go to the doctor because we’re suffering and need help, but then we’re put on this roller coaster. We’re told generic is the same as the brand name but it’s NOT. So we continue to suffer and think we’re going crazy and we have to go back and forth with our doctors trying to get what we really need. It’s not right that they keep doing this. I know that the generic brand doesn’t work for me because I’ve tried it several times (a waste of a lot of time and money!), so I pay for the brand name even though it’s a lot more expensive.
    Last time I went to the doctor, he wrote DAW on the RX and sent it to Express Scripts and Express Scripts sent me generic anyway. When I called Express Scripts they said they called my doctor for permission to give me generic and he gave them the okay. All without checking with me. I might as well be taking nothing because that’s the effect that the generic brand has on me. I feel terrible for people that don’t know this and go to the doctor for help. People have been suffering with this for years now yet they aren’t doing anything about it. When is it going to stop? It’s not right! :(

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