Questions tagged [caffeine]

A crystalline compound that is found esp. in tea and coffee plants and is a stimulant of the central nervous system.

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28
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2answers
52k views

Why do I feel shaky after only a small amount of caffeine?

I like coffee, but caffeine seems to 'wire' me much more extremely than most other people. I feel energized or even shaky after less than half a normal cup, and a whole 8 ounces will usually cause me ...
19
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1answer
334 views

What effect does long-term caffeine use have on memory?

I've seen plenty of references to the same study of how caffeine benefits memory after one day of use (1) (2) (3), but what about long-term use? There are all sort of factors to long-term use such as ...
13
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1answer
7k views

Does decaffeinated coffee inhibit iron intake as much as normal coffee does?

Apparently, coffee consumption can inhibit iron intake and in some cases is even linked to iron deficiency anemia, as Wikipedia says. It is unclear to me, however, how this happens. On the page about ...
11
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1answer
1k views

Alternative to caffeine - same effects, different chemical

I seem to have a problem with caffeine. I tend to experience a lot of the negative effects, like diuresis, extreme hunger suppression and paranoia, at two or three cups of coffee, while I don't ...
11
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1answer
1k views

Why does caffeine make me sleep better?

I have self-administered around 4 mg/kg of caffeine (peroral), and around two hours later I fell asleep, being just a little bit sleep-deprived. After around five hours of sleep I found myself awake, ...
8
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1answer
168 views

Water vs. Coffee when hungry at work

On occasion I will not have time to eat breakfast or forget to pack a snack before work. While sitting at my desk, I can hear my stomach rumbling and I have a higher tendency to daydream or lose focus ...
8
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1answer
53k views

Can coffee worsen or trigger a cough? [closed]

I had dry cough for a week now, haven't taken any meds for it and drinking 3 black coffees in a day is a routine for me. A friend told me it could worsen my cough, but she can't elaborate why. I ...
8
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1answer
3k views

Light Sensitivity as a result of Caffeine Intake

Is it possible that caffeine as a psychoactive chemical could produce an effect of light sensitivity in an individual or worsen an already present condition of light sensitivity? More specifically ...
7
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1answer
2k views

Did science backtrack regarding coffee causing dehydration?

The question below highlights recent studies that conclude coffee does not necessarily dehydrate. Is decaffeinated coffee a diuretic? Why has it always been assumed otherwise? Perhaps the evidence ...
7
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1answer
4k views

Can caffeinated shampoo have a noticeable effect?

I recently picked up some new shampoo and didn't notice that it included caffeine. I'm curious if this is just a marketing gimmick. Does having a small concentration of caffeine on my scalp for 30-60 ...
6
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2answers
2k views

How much space should be in between taking an antidepressant and drinking coffee?

For stimulants such as Methylphenidate and coffee, it is at least an hour, so I read: Stimulant + Stimulant = Stimulated. Don't take your Concerta with coffee in future. Space them out at least ...
6
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2answers
102 views

What is the amount of caffeine in the human body over time?

Let's say I know how much caffeine I drank and when. Just knowing my sex, weight (and maybe height), what is the best estimate for how much caffeine is in my system now? For example: Suppose I drank ...
6
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1answer
219 views

Does tea cause gags?

It's been a personal experience. I am at home now and take tea twice a day. For 2 months now I have been having acidity problems, which, my doctor told me, were the main reason I have been getting ...
6
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1answer
228 views

Should people with tachycardia avoid caffeine?

Well, caffeine increases the resting heart rate. If the resting heart rate of a person with tachycardia is 110 bpm, it may increase to 125 bpm after consuming 200 mg caffeine. My questions: Is having ...
6
votes
1answer
92 views

Does caffeine have any distinct biological effects to adrenaline?

Adrenaline usually is a "panicking response" and should, as far as I understand it, supresses any feelings of tiredness. However, someone I know has agoraphobia, which when triggered releases a lot of ...
6
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1answer
100 views

Is Moderated Caffeine Good? (if so how much and how often)

I have never engaged in caffeine except in rare circumstance where I take Excedrin due to a headache/migraine. However, after reading about the enhanced mental state from caffeine and trying a cup of ...
5
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1answer
260 views

Difference between Caffeine high dosages (800mg) and Adderal for ADHD?

I have ADHD. I found that 800mg caffeine / day helps me stay alert and concentrated. I don't get jittery and I'm able to fall asleep normally. I have read that Adderall and Ritalin sometimes do ...
5
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1answer
21k views

What is wrong with taking coffee and methylphenidate together?

I think this question is related to my other question here Concerta or other kinds of methylphenidate can be and is seen by some to be several cups of a coffee in one pill. Provided my understanding ...
5
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1answer
145 views

Is there a (quasi-)healthy way of resisting sleep?

I often find myself working on projects late into the night. The problem I have is that at some point, I almost always crash. I'll start feeling tired, and half an hour to an hour later, I'm out like ...
5
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1answer
135 views

Can caffeine induce sleepiness instead of wakefulness?

I notice that when having slept for a little bit of time and I am drinking caffeine, I may get instantly alert, but after few minutes after drinking the coffee, I still feel extreme urge to sleep! ...
4
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1answer
84 views

Why does caffeine raise your blood pressure when it's a diuretic?

Why does caffeine raise your blood pressure when it puts your kidneys into overdrive?
4
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1answer
10k views

Stomach ache after drinking tea [closed]

I always get a stomach-ache after drinking tea that contains actual tea (so not from fruit tea or herbal tea). Google searching told me it would probably be because of the caffeine or tannins. How ...
4
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1answer
58 views

Caffeine tolerance [duplicate]

I've noticed that the consumption of caffeine increases my productivity and improves my mood. That being said, I'm wary of acquiring a tolerance - I would like to take a low enough dose infrequently ...
3
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1answer
131 views

How to reduce half-life of caffeine?

Caffeine has a typical half-life of 5–6 hours, but some of us take much longer to metabolize it (1 cup of coffee at breakfast can leave me sleepless that night). I know I can cut the caffeine's half-...
3
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1answer
41 views

ADD medication (Dexadrine) safe to drink with low-caffiene (Mountain Dew)?

I am an adult with ADD, and I have been prescribed Dexadrine (both long-lasting and short-lasting). Now, I don't consume a lot of caffeine (I don't drink coffee, tea, or energy drinks), but I do have ...
3
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1answer
828 views

Mechanism of action (MOA) of Caffeine

Most people get a temporary increase in wakefulness or better ability to concentrate after caffeine intake. There are several known mechanisms of action to explain the effects of caffeine. The ...
3
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1answer
49 views

Risks of Caffeine Powder

I'm genetically predisposed to early onset osteoporosis, so I'm trying to cut back on acids in my diet. Coffee is a big one, but I'm also still in school so I'm very attached to caffeine. Would ...
3
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1answer
33 views

Does caffeine reduce mass gaining by accelerating metabolism?

Does caffeine reduce the effects of weight lifting on mass gaining by activating metabolism, either for every individual or more specifically for ectomorphs who already have fast fat burning ...
3
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1answer
99 views

Which is better for health tea, water tea or milk tea? [closed]

From which of the following is better for health : tea with milk or tea with milk and water in equal proportions and spices or tea in water with spices, If someone can link to some authentic source ...
3
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0answers
60 views

Caffeine's role in fat oxidation

Seen here: http://ajcn.nutrition.org/content/79/1/40.full It is stated: In agreement with the results of previous studies (1, 20), the present study showed that caffeine ingestion increased ...
3
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0answers
636 views

Types of Coffee and Headaches? [closed]

I love my coffee. Though, when I have it, I get a headache. This was quite disappointing so I stopped drinking it. Without thinking, I recently (a couple of months since stopped drinking) bought ...
2
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4answers
3k views

If I get COVID-19, can I still drink coffee? [closed]

In this link Mentions Take these steps to monitor your health while you stay home and practice social distancing: Stay home, except to get medical care. Get rest and drink plenty of fluids. ... Get ...
2
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1answer
130 views

How can caffeine cause nausea?

If there is no milk involved, it is not from lactose intolerance or something like that. What is the mechanism for caffeine causing nausea?
2
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1answer
56 views

Is there a standard about maximal caffeine concentration for synergistic painkiller preparations?

Synergistic painkiller preparations are common world wide in the following combination drug forms, for example: paracetamol-ibuprofen-caffeine paracetamol-codeine-caffeine aspirin-paracetamol-...
2
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0answers
45 views

Is guarana more potent than ordinary coffee? [closed]

As my fatigue increases, I am looking into natural stimulants. In particular guarana caught my eye. I never tried it so far. Is guarana more potent in preventing/alleviating fatigue than coffee?
1
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1answer
56 views

Can drinking alcohol release stored caffeine? [closed]

Several people in my family are sensitive to caffeine. I can't sleep if I have coffee in the afternoon, and dad won't even each chocolate. A few times recently I've noticed I can't sleep well at ...
1
vote
1answer
105 views

Does L-theanine increase caffeine's half-life?

Does consuming L-theanine with caffeine, either in drink (like matcha) or in pill form, affect the half-life of caffeine? All I can find about these substances ares claims that L-theanine slows the ...
1
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1answer
56 views

How much caffeine intake a day is still safe for health?

My question is: how much mg of caffeine (as found for example in Nescafe) consumed per day is still considered safe for health? When taken in excessive amounts what can be the harmful effects? Are ...
1
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1answer
95 views

How does coffee affect blood sugar levels?

My girlfriend has a question: Trying to figure out (on my own) if I have a problem with my blood sugar. To that effect I have just bought a home testing kit to run post-meal sugar test (like they ...
1
vote
1answer
28 views

Does chronic caffeine use increase or decrease blood flow to connective tissue?

In the short term, the effects of caffeine are well studied both as a vasodilator and vasoconstrictor, but given that chronic use produces specific adaptations, is the long term effect of caffeine use ...
1
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1answer
2k views

Monster Energy - SugarFree - vs coffee

I am wondering how Monster Energy Zero Ultra (or any of the sugar free) monster's compare with generic coffee. When I was in Highschool, I was working 50+ hours, attending high school, and working ...
1
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0answers
23 views

How does MCT (Medium Chain Triglycerides) oil + caffeine biologically provoke accelerated entry into ketogenesis? [closed]

Some years ago while experimenting with MCT oil and caffeine, I found that after a night's sleep and in a state of natural fasting (not eating for ~10 hours), I have been able to reliably enter into ...
1
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0answers
30 views

What is the mechanism of acute caffeine tolerance?

I'll admit this curiosity is based on a personal experience I'll document here, but I do believe it's an interesting and useful academic question to study and explore. For a while, I've noticed that ...
1
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0answers
125 views

Can caffeine be absorbed through the skin? Specifically, do caffeinated soaps boost energy?

I had no idea that caffeinated soap existed! (You really do learn something new everyday)! So apparently these caffeinated soaps are on the market, but are they really all that effective in boosting ...
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0answers
54 views

Caffeine vs Nicotine addiction

We, who love coffee very much, have a belief/satisfaction(could be very wrong) that coffee(which has caffeine) is better than cigarette or any other products which has nicotine. But as far as I know ...
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0answers
44 views

Is it safe to bite into caffeine tablets?

I'm taking these tablets called Pro Plus. When I swallow a tablet, I don't really feel much, but if I chew it up before swallowing it in very small pieces I feel a much bigger impact. Perhaps the ...
1
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0answers
106 views

Are low amounts of caffeine, e.g. Coke, bad for IBS? If so, advice on how IBS sufferers can get a burst of energy?

I unfortunately, am one of the many that suffer from IBS (irritable bowel syndrome). I also have the luck of suffering from fibromyalgia (so I have chronic fatigue), but I have a very demanding job ...
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0answers
47 views

Hyper activeness, simulated at work

When I'm playing games, I become very aware, maybe not the entire time, but definitely hyper. Is there certain things I can do to simulate this at work. I'm definitely motivated, and I wouldn't say ...
0
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1answer
59 views

How to avoid the diuretic effect of caffeine or green tea? [closed]

I have been incorporating green tea into my diet for a long time because of all its benefits, but I discovered that I am very sensitive to the diuretic effect of caffeine, even to the small amount of ...
0
votes
1answer
72 views

Getting rid of caffeine addiction

I have been drinking coffee for 3 years now. Due to health reasons, I want to quit my caffeine consumption. Now every morning when I don't take caffeine, I feel sleepy, drowse, and have a headache. ...