Getting a throbbing headache right around 4:00 PM or 5:00 PM is one of the most frustrating side effects of taking Adderall.

Many people assume these headaches are an inevitable part of taking a prescription stimulant. In reality, comedown headaches are almost always caused by three preventable physical triggers: dehydration, jaw clenching, or electrolyte depletion.

Here is how to identify what is causing your afternoon headache and stop it before it ruins your evening.

1. Dehydration and Electrolyte Loss

Adderall acts as a mild diuretic, causing your body to excrete water and sodium faster than normal. At the same time, hyper-focus often makes you forget to drink water for hours.

By mid-afternoon, your brain tissue experiences mild dehydration, which triggers tension headaches.

How to Fix It:

• Do not just chug plain tap water at 4:00 PM. Plain water without electrolytes can flush even more minerals out of your system.
• Drink a glass of water containing a pinch of sea salt or a low-sugar electrolyte mix around 2:00 PM to stay ahead of the comedown.

2. Subconscious Jaw Clenching (Bruxism)

Stimulant medications increase muscle tone across your jaw, neck, and shoulders. Many people clench their teeth while focusing without realizing it.

When your medication wears off, the accumulated muscle tension in your temporalis and masseter muscles radiates into your temples, causing a classic tension headache.

How to Fix It:

• Take 300mg to 400mg of Magnesium Glycinate in the evening.
• Magnesium relaxes muscle fibers and relieves jaw tension. Read our full Magnesium Glycinate Guide or check our ADHD Medication Comedown Guide for complete daily timing routines.

3. Blood Sugar Crashes

When you take Adderall on an empty stomach or forget to eat lunch, your blood glucose drops rapidly in the late afternoon. Low blood sugar triggers vascular headaches and dizziness.

• Always start your day with our 30-Gram Morning Protein Rule.
• Set a daily phone alarm for 1:00 PM to eat a balanced lunch even if you do not feel hungry.