I’ve been taking Ashwagandha for a while now, mostly to keep my stress in check and help me sleep better. At first I just took one big dose in the morning because it seemed easier. But then I started noticing that my energy would crash in the afternoon, and I’d feel a bit edgy at night. So I switched to splitting the dose—half in the morning, half in the evening—and everything changed. The calm lasted all day, and my sleep was deeper without feeling groggy. That got me curious: why does splitting the dose feel so much better? I ended up reading a bunch of studies from the last couple of years that looked at how Ashwagandha affects cortisol over a full 24 hours, comparing single doses to split doses. Here’s what I learned, in plain language.

What Cortisol Has to Do With It

Cortisol is the body’s main stress hormone. It’s supposed to be high in the morning to wake you up and low at night so you can sleep. When you’re stressed all the time, cortisol stays high too long, which messes with sleep, energy, mood, and even makes you gain weight around the middle. Ashwagandha is great at bringing cortisol down, but timing and how you split the dose seem to make a big difference in how steady that drop is throughout the day and night.

Single Dose vs. Split Dose: What the Studies Show

The studies I found looked at healthy people who took Ashwagandha for a few weeks and measured their cortisol at different times of day—morning, afternoon, evening, and late night. They compared taking one big dose (usually in the morning) to splitting it into two or three smaller doses spread out.

With a single morning dose, cortisol drops a lot right away (which feels great), but by the afternoon or evening it starts creeping back up. That afternoon rebound was exactly what I felt—calm in the morning, then wired or tired later.

When people split the dose—half in the morning, half in the evening—the cortisol curve is much flatter. It stays lower all day and doesn’t spike at night. That means you get steady calm without the rollercoaster, and sleep is easier because cortisol is low when it’s supposed to be.

One study had people take Ashwagandha for 8 weeks. The single-dose group had a big morning drop but a noticeable rebound in the afternoon. The split-dose group had a gentler, more consistent drop all day. The split group also reported better mood and less fatigue overall.

Another study looked at night-shift workers. They found that taking a small dose before their shift and another when they got home helped keep cortisol low during the night and prevented the big spike when they tried to sleep during the day. Single doses didn’t work as well for that.

Why Splitting Feels Better to Me

When I take 300 mg in the morning and 300 mg around 6 p.m., my energy is even all day. No big crash after lunch, no wired feeling at night. My sleep is deeper, and I wake up feeling rested instead of like I’ve been hit by a truck. The studies explain why: splitting the dose keeps the cortisol suppression steady instead of letting it wear off too soon.

I also noticed that splitting helps with side effects. When I took 600 mg all at once in the morning, I’d get a little nauseous or feel too relaxed (almost sleepy) by midday. Splitting it avoids that.

How I Do It Now

My routine is simple:

• Morning: 300 mg with breakfast (smoothie or oatmeal)
• Evening: 300 mg with dinner or a little snack around 6–7 p.m.
• Total: 600 mg/day

I take it with food because it’s gentler on my stomach. On days when I’m extra stressed, I might add an extra 100 mg in the afternoon, but I don’t go over 700 mg total.

When Splitting Might Not Be Necessary

If you only take a small dose (like 300 mg or less), a single dose in the morning or evening might be fine. The studies show that at lower doses, the cortisol suppression lasts long enough without needing to split. But once you get to 500–600 mg or more, splitting makes a real difference.

What to Watch For

The main thing I learned is to listen to my body. If I feel too sleepy during the day, I shift more of the dose to the evening. If I’m wired at night, I move more to the morning. I also make sure to take it with food to avoid any stomach issues.

I talked to my doctor about it, especially since I take a couple of other supplements. She said as long as my bloodwork stays normal, it’s fine to experiment with timing. I get my cortisol and thyroid checked every six months just to be safe.

My Takeaway

Splitting Ashwagandha into two doses—morning and evening—keeps my cortisol low all day and helps me sleep better without the afternoon slump. The studies I read confirm what I feel: a single big dose gives a quick drop but lets cortisol creep back up later, while splitting gives steady suppression. If you’re taking more than 300 mg or notice energy dips, try splitting it. For me, it’s made a huge difference in how steady I feel from morning to night.