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Generic vs brand name Effexor – differences for some people

<Originally written 8/21/09 – moved from another site which was taken down, yet attracted a lot of comments.  Here’s a fairly standard disclaimer:  The content of this website is provided for general informational purposes only and is not intended as, nor should it be considered a substitute for, professional medical advice. Do not use the information on this website for diagnosing or treating any medical or health condition. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider.>

Found an interesting article:
Comparison of Pharmacokinetic Profiles of Brand-Name and Generic Formulations of Citalopram and Venlafaxine: A Crossover Study

Typically I find Journal of Clinical Psychiatry to be biased towards pharmaceutical companies, so this may be just one more example. The authors receive grants and funding from multiple pharmaceutical companies but I doubt any of it comes from the generic manufacturers.

Nonetheless, it likely is a valid result and it is a very straightforward study. The results are concerning, yet understandable. Basically, the long acting Effexor XR produces lower blood levels than the generic version, novo-venlafaxine XR 75mg at a fixed interval after ingestion (they don’t mention the time in the abstract, and I will assume it was selected shortly after ingestion to maximize the chances of finding an impact of long acting formulation vs an immediate release formulation). Because the steady state blood levels are the same, I’d say that the effect on treatment is minimal; however, the abstract makes a point of saying that the generic group had 3x the reported side effects, which would fit with a higher blood level. I’m curious what the rest of the article shows as far as which side effects were more frequently reported and whether they were mild, moderate, or severe.

My understanding is that the FDA is supposed to make sure that not only are the pill contents of the active ingredient are the same (which in this study they were) but also that the delivery time is similar. I’ll need to do a bit more research into this.

The bottom line in my mind is that even if the release times are different, the active ingredient is the same and the dosage and timing should be able to be adjusted to have comparable efficacy. It is probably a non-issue when first starting out with the medication (perhaps starting with a lower dose or BID dosing until steady state if you know the formulation doesn’t have as much of delayed release), but this is more of an issue if someone has been on one formulation and is switching to another.



Just to follow up, the FDA does require testing to show that the generic has the same bioavailability as the brand name drug.

You can get the full details here (link removed 9/6/19 as no longer active) on the FDA website.

From the above referenced page on the FDA website:

MYTH: Generics take longer to act in the body.
FACT: The firm seeking to sell a generic drug must show that its drug delivers the same amount of active ingredient in the same timeframe as the original product.


One way scientists demonstrate bioequivalence is to measure the time it takes the generic drug to reach the bloodstream and its concentration in the bloodstream in 24 to 36 healthy, normal volunteers. This gives them the rate and extent of absorption-or bioavailability-of the generic drug, which they then compare to that of the pioneer drug. The generic version must deliver the same amount of active ingredients into a patient’s bloodstream in the same amount of time as the pioneer drug.

So, according to the FDA, adequate studies must be provided to show that the generic drug is equivalent to the brand name drug. The above referenced study seems to indicate that the blood levels were higher in the generic group and that side effect rates were higher. The question is who to believe? My own bias is against the pharmaceutical companies as they have an inherent bias in supporting studies that will be to their favor. The authors of the above referenced study have received grants and support from the manufacturer of Effexor (Wyeth). My own impression (and just my opinion) is that Journal of Clinical Psychiatry tends to publish articles that favor the pharmaceutical industry.

Nonetheless, the article has served its purpose in created doubt amongst people that the generic drug may not be equal to the brand name.

After doing a little more research, it is interesting that they did not find differences in bioavailability between citalopram and Celexa. The history of this finding was interesting enough that I’ll be creating a separate thread here on the topic soon.


5/26/11, posted by a guest user named 12perlam

i have been taking effexor xr brand name for 5 years…some time this winter i renewed a prescription…. within a week i had the increasimg sense that there must be something wrong with the batch of meds i picked almost as if maybe in the manufacturing process there had been less meds in each capsule.
i returned to pharmacie…the pharmacist explained …that because there had been a back order on effexor brand name , they had given me the generic brand.

i was very reactive to the change…they put a note inmmy file and promised not to give me ,generic, again…

three weeks ago i filled another prescitpion…this time they gave me brand name but the only dosage they could provide was insted of 2 capsule of 150mg each which i had been taking at bedtime..they gave me 4 capsules of .75 mg each which i took at bedtime…i did not consider that this might impact me since it totals to the same 300 mg x 1 per day.

well, my brian has been all over the place…i,m reactive to every mini stressor…as if i,m in another depression…barely able to concentrate….so today after coping for the past 10 days or more….i stopped writing in the middle of an email..and wentover to the pharmacie thinking they must have agsin given me a generic during all the confusion over the back order….but this was ot the case…the pharmacist explained someting about the time it takes for the release of these .75mg capsules…he asked me to try to change the dosage from 300 at one time…to take it 150 x twice/day.

all this to say ..i am surprised to hear that there are tose out there who believe that generic and brand name are ,such close, replicas…I don,t feel that this is so….i guess some of us are terriblly sensitive to minor medicinal changes.
thank you


From 7/18/11 posted by a guest user named mree:

12perlam – you are not crazy. I had to switch to the generic Effexor last April because my insurance company would no longer pay for brand name drugs if a generic version was available. I didn’t think much of it at first, but over the next 3 months – slowly – I found myself crying on the way to work, waking up at 2:00 and not being able to go back to sleep, not wanting to do my favorite things, having anxiety attacks, overreacting to everything, eating too much, shopping too much, feeling like everyone was against me and doing all sorts of potentially destructive things to my job and relationship. Finally I clued in. (Why does it always take me so long to figure out I’m depressed?)
Anyway, I couldn’t see my doc for a few weeks, so I autonomously increased my dose of the genetic effexor from 300 to 450 mg per day. (I know it is over the max allowable). Well I almost immediately felt better, but not quite 100%. I actually have used a bit more. I also noticed that the withdrawal side effects were much less, and my sex drive started to come back a little. So I am not keen on going back on Effexor. The problem is my doc says I can’t take 450mg of generic effexor. All I know is 300 mg almost killed me… My doctor said she had heard the same stories from many of her patients. I went to talk to the Pharmacist and he categorically denied that there was any difference between the two.

Hope this helps.


Posted 7/18/11 by a guest user named 2OLI:

12perlam — I was replying to “mree’s” message…but you took the words right out of my mouth, except for the too-much-shopping part, my hubby said I did that before the generic Effexor. I have tried every brand, generic brand of antidepressants over the past 15 or 20 years, and the Effexor XR fit me. I thought my troubles were over. Then my insurance company wanted to charge me $300 for a refill so I was forced to take the generic. Every since the generic, I am going through withdrawals, I’m very moody, angry, my husband doesn’t understand what is going on, then I realized, it all started about the time I started the venefexeline (sp?) which is generic for Effexor XR. My doctor tells me there IS a difference between the brand and generic. Now we are trying to get the insurance company to make an exception.

This post has helped me tremendously, I thought it was just me. And, yes, I am one of the patients that is very sensitive to medicinal changes. Please keep me posted.


Posted 7/20/11 by a guest user named seyah:

My insurance also changed April 1. So, I changed from Effexor XR to the generic. After making it through the first 2 weeks without seeing a change, I thought all was okay. But after about 2 months, I started becoming very irritable, moody, angry, feeling like I wanted to cry when stressed….mree-very similar to what you found. There is definitely a difference. I’m so happy to hear I’m not the only one 🙂 My doctor did mention to me that the generic might affect me differently.


Posted 8/8/11 by a guest user named ecomom4:

Boy am I PO’d! Yep, the pharmacist tells you they are exactly the same!

I am going 2 days without the Venlaxafine after finding out that it is causing
high anxiety and very long days. My doctor is pushing through the Effexor hopefully
tomorrow and only then will I start back. Hope I’m not setting myself up for a roller coaster
ride going 2 days without but I just can’t handle the Venlaxafine.

It just pisses me off what they’ll do to us just to save a few bucks!

Our minds are the most valuable. Give me a broken leg anyday over feeling
“out of sorts”.

Put the doctors, pharmacists, rx salespeople all on the Effexor and then switch them
around like flying yo-yos and see how they like it 🙂


Posted 8/22/11 by a guest user named sps4282:

I was taken off the Effexor XR after 3 years. I am now on the generic and cannot sleep nights, or I wake at 1-2 am and cannot go back to sleep. I am moody, do not want to do things I usually like to do, and I am PO’ed! My pharmcist told me to contact my Dr. and he could tell the insurance company I need to have Effexor and they must pay for it! At least in the State I live in..


Posted 8/23/11 by a guest user named purple13:

Hello, everyone. I am new to this board today. I joined because out of desperation i googled “generic vs brand name effexor” and this was the first hit i had.

reading your posts have made me so mad and happy at the same time that i want to cry! i have been miserable for over 6 months now, racking my feeble brain, trying to figure out what is wrong with me! i have been not been my self…my symptoms pretty much like all of you are describing. waking up in the middle of the night…moody…depressed…not doing the things i enjoyed. i have been on effexor and lamictal for years now and it had worked so well for me! and all my problems i realize started shortly after i had to start taking generics! i am so MAD i could spit! i have pondered suicide many many times and all of my relationships and work have suffered – all because of THIS. i am NOT going to take this anymore! i am calling my doctor and going after my insurance company to let me try switching back for a month to see if it helps, and, from what i’ve read here i am betting it will help.

BLESS ALL OF YOU for your posts. i finally feel hope.



Posted 9/1/11 by a guest user named meowsers:

Hi everyone,
Just wanted to let you know that I am experiencing the same issues with the generics as everyone else. I am crying on minute and happy the next. I refuse to take an increased dose of effexor.. I have not changed since 2002. I have been steady on 150mg since 2002 with no need to increase,
I switched to the generic , due to my insuranc company… and have bee depressed since. I have the brain zaps, stomach nausa and the tears at random moments…
I need to know what to do, I am at a loss with this.. I am currently fighting with the insuranc co. to have it fixed..ugh.


Posted 9/2/11 by a guest user named LynHinABQ:

Wow. I’ve been surfing for days, trying to evaluate, objectively, the generic Venlaf. vs. Effexor. I too HAD to switch from 15 years on Effexor (saved my life/brain) to generic due to health plan change – and 1 75mg daily, vs 3x daily before. I changed once before (another, kinder insurance) to save money but went back to doctor saying I can FEEL the difference and it was negative – twitchy; sad, crying…everything everyone is saying here. I went back to Effexor and immediately bounced back. Then, 7/1/11 change in health plan – Effexor not even on the formulary; struggling with generic while I file my appeal and fight the system; gather documentation. Even my pharmacist said..oh my, they are doing this to you? That is forced titration, not healthy, studies show there is NOT bio-equivalency etc. She said she’s hearing this ALOT from patients.

I’m not sure how I get a reply from this site or more suggestions; I’ll flag the site and monitor it. But I definitely wanted to offer my input/experience. And, is it me or…I am TIRED..bone weary, rag-doll tired — again I feel I can directly correlate it to the change in my meds. My dr. appointment is 9/12th; very supportive doctor so hope he’ll write up a good prior auth to at least up my generic from 1 a day to 2, tho’ 3 is what has, historically, worked for me (crash with less than 3 effexor also…). But with Effexor not even on the formulary I’m looking at $200/monthly to stay with 3 Effextors/daily. I’m also looking into Walgreens discount membership program, and if I can get 3daily effexor for something less than full boat, I will likely pay for it, run it through my FSA and…

I called my pharmacy exception center and was crying and yelling at them saying they were jacking with my mental health, forcefully titrating me off a drug that requires much more appropriate weaning etc. They dont care….

Wow, I’m thankful I found this site. Be well, stay well, get well everyone. We’ll make it!!!


Posted 9/2/11 by a guest user named LynHinABQ:

I have to write some more – to affirm you’all ..and me. Yep – nauseated, narcoleptically tired; sad, blue, wiggy… EVERYTHING EVERYone is writing is spot on. We need to fight the insurance companies. Contrary to another post who said the pharmacist was saying it was equiv, my pharmacist is the one who is bashing it! It’s the insurance companies we need to fight.


Posted 9/7/11 by a guest user named purple13:

well, i bumped my ‘script dosage up and it has helped. not the same as before but not quite as bad. i think the generic is just not as strong. i don’t think i should recommend folks playing with their dosage of course but you might consult your doc to see if that could be an option for you. you might not want to increase but you just might have to. better than the alternative.

fyi, my insurance co in OH (laws differ state to state i think…) is that if my doctor calls express scripts and requests “ancillary override” then they WILL give me brand name. just has to have prior authorization. it would cost me over 1K per month without that override. ridiculous amount.

all of you struggling…hang in there, please! i know it’s hard.

oh, and if you’re having brain zaps you DEFINITELY ARE NOT getting enough meds in yr system and perhaps uppping dose is the way around this problem w/generic.


Posted 10/18/11 by a guest user named SandyBrain:

I’ve the name SandyBrain because that’s what it feels like when I move my eyes to quick. My brain is surrounded by sand and it grates when I move my eyes a certain way. There are other physical side effects that I recognize from my last attempt at using generics
A mounth ago I refilled my Efexxor XR 150 mg which usually costs $20 dollars. This time the cost was $160 dollars; needless to say I freaked. Every year my doctor has to submit justification for real drugs instead of “crap in a capsule”…I had let the authorization expire.
I had tried generic Effexor and the dosage had to be so high to be effective it wasn’t safe.
I asked for the appropriate forms from BCBS and was going to take them to my doctor. I didn’t and got stuck with the generic.
Now I’m in such a state, I wasn’t sure if I would be here tomorrow. Coming across this discussing has given me the idea of taking 1 150mg in the morning and 1 150mg in the evening. I’ll see tomorrow if it makes any difference. At least I now have a tomorrow.
I’ll have to get with my doc and get straightened out.


Posted 10/20/11 by a guest user named lmbr69:

OMG!! Yes! I am not imagining things! Very happy I googled this and received some justification that the generic form of Effexor XR is crap and does NOT work for me!!! Just switched back to the name brand and can’t wait to feel better again!! You have all just described the exact same symptoms I’ve been experiencing for the past 3 months when I switched to the generic form….irritable, constantly waking up at night, lack of concentration, tired during the day, etc. The name brand is definitely worth the extra money to me right now!! Wow.
Best of luck to everyone on here!!


Posted 10/27/11 by a guest user named purple13:

i am going to report my problem here at the FDA: … online.htm

if you decide to do the same make sure you have your prescription bottles available as the questionnaire asks for info re the manufacturer. it may not help but it’ll make ME feel better about this. i feel it’s a duty to report this problem! we’re the survivors…so far. how many have not made it to ponder this problem? the suicidal issues are SCARY. xome


Posted 12/19/11 by a guest user named Miss D:

I’m so glad I found this page. I thought I was going “crazy”

I’ve been on generic venlafaxine twice. I live in the UK.

Both times within about 10 days I wanted to jump out my window. I took cravings for cigarettes (I’ve never smoked) and alcohol. My panic attacks went through the roof. I had to insist on Effexor due to this reaction. I only put 2 and 2 together when I realised there was a change in packaging.

I am going to report my reaction to the BNF British pharmaceutical body and I suggest others to do the same. This generic brand could seriously harm someone.



Posted 1/9/12 by a guest user named xntricj:

I have been on generic Effexor for nearly a year, and I still don’t feel as well as I did on Effexor. I had the same side effects described in many of these posts. I thought about increasing my dosage (225) by one pill, but I’d run out of meds before the prescription refill time. It might be worth a try, since I feel LOUSY most of the time. One of my docs told me a generic medication only has to be 90% identical to the real medication; AND, the are absorbed differently, or the fillers used in the generic can be different which affect how our bodies react. I, too, am very sensitive to medication and to changes in meds. I would like to be off Effexor all together, but over the years when I try to cut back in order to wean off the REAL Effexor I start having terrible side effects. I feel like checking into a hospital and just going off it cold turkey to have it out of my life, but I know people can’t do that and can have a tough time surviving that. I wish I’d never started on these meds, but years ago when I was perimenopausal, I had to start on something. Thank you for the posts – it helps me and my husband realize what’s going on. We figured it had something to do with the generic, but we weren’t sure. What gripes my behind is the danged insurance companies can make these changes to place a life-altering, necessary medication on a list, increase the price so we can’t afford the medication, then we feel miserable on the crappy generics. Insurance companies are like the maffia in my opinion – and they’re thieves. We get continual increases in our premiums and less for the increased cost.

5 thoughts on “Generic vs brand name Effexor – differences for some people”

  1. I ordered generic Effexor XR at 150mg to take once a day as prescribed by my doctor, from Northwest Pharmacy to save money. After two months of taking the generic form, I began suffering extreme nausea, dizziness, mental “fogginess,” lost my ability to think clearly, became moody, depressed, and irritable. Motion sickness set in to the point that so much as walking down a hallway so enfeebled me that I had to sit down. After ruling out inner ear problems, migraine issues, and seeing a neurologist, we deduced that the generic Effexor was causing the problems. Sure enough, only one day after taking Effexor XR instead of the generic, my symptoms began to subside. Three days later, I was as good as ever.

  2. I too have just searched Generic vs brand name Effexor and came upon this site. My situation is opposite. I am experiencing my second bout of chronic depression, the first being 2008 because of health conditions with my hubby (liver transplant from Hep C from blood transfusion) and death of my sister (same day as my hubbys surgery) and the death of my mom three months later. I was prescribed Teva Venlafaxine XR. I started with 37.5 and worked my way up to 225. I took them for 18 months and decided to titrate off (with the OK of my doc). I did it very incrementally and slowly and had no problem. Things were fine until 2011 when I noticed (as well as my family) that I was very irritable etc. which was opposite of the first time when I became very, very low, crying, afraid, no appetite, (lost 20 pounds) didn’t want to go out or see anyone etc which I call the bottom of a dark hole. I have read that with Chronic Depression the chances of experiencing a second bout are high and with a second the chances of a third are high etc. Thus the “chronic”. Second time around I have also included counselling and self instructed CBT. I believe they are key but am prepared to accept that I may have to take ADs forever. (Input on this factor would be appreciated) I am taking the same generic as before but with different side effects. Wicked insomnia which I have take prescription meds for (Zopiclone, Trazadone). I tried OTC both benz and the other and they gave me terrible restless leg snydrome and didn’t work. I have no appetite again but this time have gained 20 pounds. I have a new doc and she had me do a teleconference with a psychiatrist who confirmed my depression and suggested I take name brand Effexor XR. We do not have insurance but are on the Trillium Drug Program (which here in Ontario liver transplants have to have) because no one, I mean no one can afford the drugs he has to take forever. This plan includes family so I am covered. But as with private insurance it only covers generic unless otherwise stated (except my hubbys). Name brand Effexor XR is not included. My doc applied for a Pfizer card and they cover the difference.
    So-o-o-o I am going from generic to name brand and would like to hear if anyone else is or was in this position and what the changeover was like. Things like appetite, weight gain, insomnia etc while taking the brand name. What is life like for you on name brand Effexor XR, what is your diagnosis, amounts etc? I do not take any other drugs. I look forward to your responses and wish everyone success in their challenges.

  3. To all those suffering from the generic, I feel your pain as I to have been miserable since being switched to the generic. The good news is that if you go to EffexorXR.Com website you can get a $4 co-pay card. Now the caveat is it will cover only up to $1000 per year out of pocket costs and $75 for retail pharmacy refills $225 for 90 day mail order pharmacy. Even though it is still very expensive to get the brand name drug, at least now we can all save some $$$. Hope this helps..

  4. Thank God I found this website! Now I know why I have been feeling awful. I have had all the same symptoms as others on here. I will be switching back to Effexor ASAP. I don’t care if it costs me more than the generic. It all makes sense now. I started feeling terrible not long after I switched. Even started having suicidal thoughts again. Will see if I feel better after changing, I am sure I will. Thanks everyone for your input.

  5. I so agree with you. I don’t care what the doctors or pharmacists or anyone says, there is a difference between brand name and generic. Some people are probably just not as sensitive as others. Does that make us bad people or hypochondriacs? I took the generic of Lexapro and Effexor; I experienced ringing in my ears, music playing in my head and muscle aches. I noticed when I missed a day of the Effexor I became extremely nauseated, sweating, and just a host of flu like symptoms. It reminded me of how a drug addict explains detox! Thank you for your post.

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