How long does It take for BENADRYL to Work? – Benadryl to Kick in

How long does It take for BENADRYL to Work

How long does It take for Benadryl to Work? Benadryl, if someone would want to know what is it used for, a simple answer to this would be to get rid of allergies.

People who are allergic have a sound immune system just that they are slightly more reactive. It thus releases chemicals like histamine so as to get rid of substances named Allergens, which are usually harmless.

Mostly seen in the case of allergy, people start experiencing inflammation in nose, eyes, and mouth. This happens as histamine triggers the human body to move the allergens out and the route through which this happens is where inflammation is experienced.

If Benadryl is taken by mouth, then it needs 15 to 60 minutes to work, When injected into a muscle, it takes 20 to 30 minutes to work, but if it is injected through vain it works immediately.

But Before knowing how long does it take for Benadryl to work, we should be a correct judge of whether Benadryl is needed in a particular case. This can be done by knowing the symptoms of allergies. The majority of allergy caused in a human body is due to the air we breathe. The most common symptoms include: –

  1. Itchy Throat
  2. Runny Nose
  3. Itchy Nose
  4. Itchy Eyes
  5. Sinus Pressure
  6. Sneezing

Benadryl offers a variety of products which can be used based on the symptom one is experiencing, as allergies are the most significant contributors to these symptoms.

The last resort to get rid of allergies should be using medicines. This is the time when we should know about Benadryl and knowing the fact that how long does it take for Benadryl to work. But even before we get to the last resort, we should be aware of the causes of allergies and should be cautious of them.

Allergies are caused by allergens and the most troubling fact is that allergens are present everywhere. The most common allergens include pollen, dust mites, mold spores and pet dander. We should be aware of the fact that there is no way we can get rid of allergies, however, we can be aware of the factors which contribute to developing allergies.

The most common allergies can be broadly divided into two halves: –



Seasonal Allergies are the ones which often flare up seasonally. They are triggered by mold spores and pollens from trees, grass, and weeds.

Year-Round allergies are triggered by dust mites, mold, pet dander and mildew. This kind of allergies mostly hit us when one is indoor.

Benadryl comes in different types. It comes as tablet, capsule, liquid, spray and gel. Benadryl products are broadly classified into an adult product and children product. These different products have different answers for “how long does it take for Benadryl to kick in?“. We will talk about that in the article but before that let’s discuss on few other topics like side-effects.

Benadryl Side Effects

Unlike any other medication, Benadryl has its own set of side effects. It includes Drowsiness, dizziness, constipation, stomach upset, blurred vision, or dry mouth/nose/throat. If any of these effects persist or worsen, consult your doctor or pharmacist promptly.

In order to relieve dry mouth, suck hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute.

If your doctor has directed you to use this medication, remember that he/ she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including mental/mood changes such as restlessness, confusion, difficulty urinating, fast/irregular heartbeat.

Get medical help right away if you have any very serious side effects, including seizures.

A very serious allergic reaction to this drug is quite rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

Benadryl  Precautions

  • Before taking diphenhydramine, tell your doctor or pharmacist if you are allergic to it; or to dimenhydrinate; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Consult your doctor regarding your allergies before you start the medication.
  • Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (such as asthma, emphysema), high pressure in the eye (glaucoma), heart problems, high blood pressure, liver disease, seizures, stomach/intestine problems (such as ulcers, blockage), overactive thyroid (hyperthyroidism), difficulty urinating (for example, due to enlarged prostate).
  • This drug may make you dizzy or drowsy or cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Avoid alcoholic beverages.
  • Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
  • Liquid products, chewable tablets, or dissolving tablets/strips may contain sugar and/or aspartame. Liquid products may also contain alcohol. Caution is advised if you have diabetes, liver disease, phenylketonuria (PKU), or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely.
  • Children may be more sensitive to the side effects of this drug. This drug can often cause excitement in young children instead of drowsiness.
  • Older adults may be more sensitive to the side effects of this drug, especially drowsiness, dizziness, confusion, constipation, or trouble urinating. Drowsiness, dizziness, and confusion can increase the risk of falling.
  • During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
  • This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.

These were the few things you must know before consuming Benadryl. Also, always consuly with an expert before starting any medication. It helps you stay away from even the rarest or slightest danger.


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