I won’t even go into my drama but a fast way to narrow things down if you think it’s allergy, include vaping straight PG, note how it makes you feel. Then straight VG again taking notes. If there’s no issue mix at the rate you prefer and add your nic, if there’s no problem then you know your issue possibly lays with a flavoring. Depending on how vast your pantry is it could take a while to narrow that down but it is possible.
When adjusting your nicotine levels remember your set-up varies how much you’re getting so if you’re sub-ohming no higher than 6 mg. is recommended.
I got sick 6 months after beginning to vape so the vape was the first place the finger was pointed…I know how to pin down allergies now 
… After all that work however it had nothing to do with the vape. LOOK AT ANYTHING THAT’S CHANGED INCLUDING MEDICATIONS! Good Luck!
Hello guys,
I was just looking to see some reviews about E-cig ,
What this man saying here it’s what exactly happen to me it’s making me super sleepy when I’m vaping , i stop smoking about a month ago and start E-cig i use to smoke more cigarettes to keep me awake when i was driving but now vaping is making me so sleepy and drowsiness even caused me losing my dream job! I’m so upset now i wish i never start E-cig and continue with cigarettes, vaping nearly caused me a fatal car crash because it made me so sleepy
I use to drive gor very long hours n never feel slerpy when i use to smoke reall cigarettes.
Well I hate to be a downer on the quitting smoking,vitamin D3 ,diabetes,hyperthyroidism being culprits but I starting vaping 2 years ago in hopes to quit smoking,noticed the sleepiness so I knew I couldn’t vape while at work so ended not quitting smoking. I don’t have diabetes or hyperthyroidism,yet still 2 years later still get the sleepiness which stinks cause I’m back to wanting to quit smoking but unfortunately can’t use vaping to help because of the sleepiness it causes.
Hi there
Just read this post. Did you find out the sleepy reason?
I am having same issues and vape. Wonder if it’s that for me?
same here smoked 43 years 20 months cigarettes / tobacco free how much Nic in your mixes?
I’m down from 18 to 10 MG right now
Also type 2 diabetic, possible have your A1C checked and determine if Diabetes is present. If so as I ended up doing is if your using sweeteners other than liquid stevia etc… In your juices. I’d stay clear of other sweeteners personally in my situation. When I was buying “Premium” Juices I found out that they where loading down recipes with real sweeteners my sugar was spiking up in the high 400’s and straight back to sleep I’d go. Now since I’ve been DIYing I control what goes into my juice & I’ve had no more sleeping issues. JMO I hope this helps. Be safe,careful & vape sugars Free
Experience for me … EVERY time I quit smoking, I found sleepiness increased for quite awhile.
Good info in this thread! Not a doctor or nurse but I have chronic low energy problems, so it’s a much researched issue!!
Today, I attribute mine to mental/behavioral disorders of depression, anxiety, ADHD and disabling insomnia. There are 3 types of insomnia that most don’t realize, so I always try to educate people on this aspect.
A blood test for thyroidism is called for with extreme fatigue.
Body chemistry is a fascinating and powerful thing! Dopamine is a particular issue that controls so much of what we deal with using nicotine and caffeine, which are highly addictive substances. I take Wellbutrin daily (which promotes more dopamine in the brain and it an antidepressant unlike most and, very relevant here, is prescribed as Zyban to aid in tobacco/nicotine cessation) and find it curbs usage of other addictive substances, like alcohol.
But, most important in my education on energy and motivation levels, I always try to remember that anything in the body that creates a rapid increase in energy, like sugar, caffeine, nicotine, or even anxiety, will bring on a huge crash afterward. I’d consider extreme fatigue to the result of nicotine overdose and then withdrawal.
Lastly, nicotine and other appetite suppressants also wreak havoc on our appetites and water consumption. It’s simplistic but a lot of us don’t realize it but just not eating or drinking enough liquids during the day are dramatically tiring.
I’m interested to learn from others how they solved fatigue problems!
Hello I felt the same 3 years ago. Never happened again. I am vaping at 30 mg nicotine. Maybe you need try higher nicotine. Or maybe the vape juice you use as too much sweetener? Nowadays there are different sweetener types. Try a different brand of ejuice , take notes and observe. I cannot day why I don’t get the sleepy feel anymore. Maybe because I use a different brand ?
Cheers
Philip
I’m hesitant to answer this because solution depends on the cause, and "one man’s meat is another man’ poison " very much applies here.
I personally suffer from exericise intolerance and fatigue on account of an inborn error of metabolism. Now that I understand the cause, I can control it (but not exactly “solve it” )by means variety of self-help techniques. the most imporatant, perhaps being my adoption of a very low fat/ very high carb diet. For a diabetic, for instance, my diet would be dangerous! For me, it’s a life-saver.
Interestingly, ever since I started smoking (at around the age of 17) I’ve found that nicotine helps to lift the associated “brain fog” and improve my cognitive function. I never used to admit that, cos I knew that no-one would believe me , but research is now starting to back me up!
I tried Zyban once in a misguided effort to give up, and had an allergic reaction to it. But before the allergic reaction kicked in, I found it’s effect on me very intersting:
The advice was tii carry on smoking as usual for the first couple of days, so I did, even though the Zyban reduced the craving considerably, So this wasn’t because I;d given up smoking, but rather the action of the Zyban on me, but I found that I was getting all my usual quitting symptons in buckloads; that is, I was becoming extremely dopy and absent-minded, to the point that I just couldn’t function normally.
Obviously my neurochemistry is somewhat idiosyncratic, so that might say more about me than it does about Zyban , but I think at very least, it underscores the imprtance of listening to your own body.
Some people on this planet (quite a lot of us , i believe) do use nicotine as self-medication, and our “withdrawal symptoms” , in that case, largely consist in a resurgence of whatever problem the nicotine was mitigating.
I shouldbn’t be surprised if it turned out that the OP’s issue was caused by reduction in nicotine consumption,just as he speculated, People often get very sleepy when they give up caffeine - another stimulant. This usually resioves with time, . I hope it did But if the nicotine was maskting some pre-etistng issue, then time wouldn’t have so much effect, would it?
Hmm. I wouldn’t leap to conclusions re, cause and effect , Those problems are common co-mordities, or symtoms of various systemic disorders that include fatigue amongs their symptoms. Or , hang on, maybe that’s what you were actually saying, and I mistook your meaning?
Anyway , i can check all those boxes (though I have the sort of ADHD that effectiveky skips the H 
) and add a whole bunch of others. You might have something similar to myself, in which case good luck with getting a dx. You’ll need it! That whole area is under-researched and underfunded :(.
Yeah, that’s what I was saying. And, exactly to your point of using nicotine to self-medicate, I’ll add a short story.
When I was in graduate school, I’d go to a coffee house everyday because it was particularly quiet and had few customers. I met my best friend there as we both chain smoked and drank refills outside all day.
Shortly thereafter, I was diagnosed with ADHD and started medication. I found out my buddy also had ADHD (unmedicated) and we were both using massive doses of nicotine and caffeine to pay attention to our work!
I just wonder how many others are without realizing it.
Hey, I’ve experienced the same thing and have been getting the same stupid replies. You’re depressed, chronic fatigue, have you had your bloodwork done?, etc etc.
But I’ve conclude that it’s the PG. I was using Snow Plus for almost a year and they use mainly VG and I never experienced what I experienced when I switched over to buying bottled vape juice. The only difference I’ve noticed is PG vs. VG.
So as far as my experience is concerned when I vape on and off for an hour or two I start to get super tired. Almost as if I’ve been drugged. It’s the weirdest thing. I can barely keep my eyes open and have to force myself to stay awake.
So I’m switching back to Snow Plus but it’ll take a week or so to get to me. For right now I’m just taking small hits of the PG heavy vape juice, and I’m just hitting it less often. But to be honest with you, even after one hit I still feel a little lethargic.
So start there. Switch to mainly VG liquid and see if that helps!
Welcome aboard.
The replies are intended to be as helpful as possible, and aren’t ‘stupid’. Folks are just trying to help out. And if this is a backhanded vendor plug, calling people stupid may not get you the Google-Fu action you desire.
So 601vapers did you find out why you were so sleepy yet?
It is obvious that vapes make you sleepy because it contains nicotine, if you are new to vape use light vape liquids or if you smoke many time reduce your smoking capability.
How is it obvious that nicotine makes him sleepy? From my experience it makes it difficult to sleep.
For people with bipolar, stimulants act as sedatives. Conversely, sedatives can have the opposite effect too. I am so very aware of this myself lol. Yes, cutting back on the nicotine will help a lot. Personally, I’m tired of passing out sitting up. I go to blink my eyes and “poof” 1 1/2 hours have past and I’ve rolled off the bed onto the floor lol.
HUH , What ??? Nicotine is a stimulant , how is it obvious
Whoa Mind Blown …Im not Familiar with Bipolar , but if OP suffers from Bipolar than maybe it is the answer , however for many Nicotine would be the opposite so its not so obvious
I’m so bipolar my Dr. thought I was faking it. It wasn’t until she started giving me all different kinds of medication for depression that it began to dawn on her I wasn’t joking. It wasn’t until I started showing ultra rare side effects of the medication (and I could describe them in detail, not just say I had it) that she realized I had it. It took her 4 years!!! They kept blaming it on my Parkinson’s but this is all together different
She tried me on all kinds of medications but the ones that had marginal successes were the ones that were off label? (when they use it for something other than stated its for). She didn’t even realize they were off label items until she got frustrated and started to look at my prescription history. She turned, looked at me and said, “Oh my god! You’re bipolar!!! No wonder! Why didn’t you tell me?!?!?” (grammar aside, she had learned engineers aren’t 1/2 bad concerning studying medicine so she actually trusted me when I recommended medications for myself).
I just looked at her and said, “I’m not a Dr… I’m not allowed make diagnoses”. I got a pillow thrown at me for that one. Quite a few medications that treat bipolar will treat Parkinson’s too. Gabapentin is one. It’s seriously twisted that it’s now a scheduled medication. (should I stop typing now? Yeah, I should stop typing now… Sorry).