Ashwagandha Side Effects

What the Research Really Says, And Who Should Be Careful.

Walk into almost any health-food store and you’ll find shelves lined with Ashwagandha. Celebrities swear by it. Influencers blend it into smoothies. And chances are you know someone who says it’s the only thing that helps them feel human again.

There’s no doubt about it. Ashwagandha is the herb de jure. But popularity brings scrutiny. For every person claiming deeper sleep, another insists it kept them awake. For every enthusiast who says they feel calmer, there’s someone else warning of thyroid swings or liver concerns. The internet’s imagination, as usual, gallops faster than the evidence.

So what do we actually know about Ashwagandha’s side effects? 

The Herb Behind the Headlines

Ashwagandha is an adaptogen. In other words, it helps the body ‘adapt’ to stress. It doesn’t sedate. It doesn’t stimulate. It simply regulates your body’s natural stress response.  

So clinical trials circle around three themes: stress, sleep, and mental clarity under pressure. And the results are always the same. Participants report that although their lives are just as demanding as before, their ability to cope no longer feels quite so fragile.

But here’s where nuance matters. Ashwagandha is not one thing. Different extracts behave differently. Some use only the root; others combine root and leaf. Some are standardized; others are little more than pulverized plant matter in a capsule. When people talk about side effects, they’re often talking about completely different substances under the same name.

To understand the risks, you have to start with the studied forms. The ones researchers have actually put into human bodies and monitored carefully.

What the Studies Actually Show

Most clinical trials on Ashwagandha run between eight and twelve weeks. And these studies consistently paint the same picture: reduced stress, better sleep, quicker sleep onset, improved resilience, and very few adverse events. The side effects that do appear tend to be minor — a little digestive discomfort, a brief wave of drowsiness, or in some cases, a momentary lift in alertness.

A handful of trials have followed participants for longer. Up to six months¹, and even a full year. In those settings, researchers have repeatedly checked the usual danger signs: liver enzymes, kidney markers, thyroid hormones, basic blood counts. If Ashwagandha were the physiological troublemaker some corners of the internet insist it is, this is where the evidence should start to crack. Instead, in healthy adults using standardized root extracts at reasonable doses, those markers have stayed comfortably within normal limits, and serious adverse events have been notably absent.

The most interesting evidence comes from a 12-month² observational study, the longest look we currently have at real-world use. Nearly two hundred adults took a standardized extract daily for an entire year while clinicians monitored their lab work. The results didn’t make headlines. And that’s precisely the point. Nothing dramatic happened. No spikes in liver enzymes, no alarming thyroid shifts, no slow-burning toxicity. A few people experienced mild, self-limiting complaints; most simply felt better.

It’s not a perfect study. It wasn’t randomized, but it aligns with everything shorter trials have suggested. For healthy adults, Ashwagandha has no adverse side effects.

The Aswaghandha Side Effects That Worry People Most

This is where reality and rumour tend to diverge.

Shortness of breath
This is one of the most alarming symptoms mentioned online. Yet it barely appears in scientific literature. Across controlled trials, long-term studies, and safety reviews, it simply isn’t a recognized pattern. When it does surface anecdotally, it tends to involve high, unstudied doses or individuals with preexisting respiratory or anxiety issues. Not something to dismiss, but not something to expect.

Sleeplessness or feeling “wired”
Curiously, clinical studies show the opposite: people sleep better. But a minority do experience a brief phase of increased alertness, especially when they take it late in the day. This is less a red flag and more a reminder that Ashwagandha isn’t a sedative — it modulates stress signalling. For some bodies, clarity arrives before calm. Adjusting dose or timing usually resolves it.

Liver concerns
In a large-scale review³ of 1,396 peer-reviewed publications on Ashwagandha researchers found that roughly 97% of the published literature reported no safety concerns. Only a tiny fraction even mentioned possible toxicity, and just about 1% touched on liver issues at all. 

Thyroid interactions
This is the one area where caution is warranted. A few small studies⁴ show that Ashwagandha can modestly influence thyroid hormones, usually nudging them upward. Healthy adults in these studies remained within normal limits and experienced no symptoms. But for individuals on thyroid medication, even small shifts can matter. So for those taking these medications, it’s best to consult with a healthcare provider before adding Ashwaghanda to your supplement regime. 

Feeling “overactivated”
If you spend enough time on Reddit, you’ll find a dozen versions of the same story –– Ashwagandha leaves you feeling wired. But when you actually read the clinical trials, the pattern looks very different. Study after study⁵ reports fewer anxious thoughts, better sleep, and lower stress scores… not nervous system overdrive. In fact, in a 60-day randomized, double-blind, placebo-controlled trial of adults under high stress, researchers noted significant reductions in anxiety and cortisol. And no signs of overstimulation in the treatment group. If anything, the people taking ashwagandha slept better. So where does the “overactivated” feeling come from? Most often from the wild world of unstandardized powders, megadoses, and cognitive-enhancement blends that bear little resemblance to what researchers actually test. In clinical settings, when you use a standardized extract at a safe dose, the nervous system doesn’t speed up. It relaxes.

Is Ashwagandha Safe Long-Term?

Yes, with caveats.

The evidence we have — up to twelve months⁶ — shows no accumulating toxicity in healthy adults using moderate, clinically studied doses. Lab work remains stable. People often feel progressively better. But we don’t yet have multi-year data across massive, diverse populations, so humility is essential.

So for most people, long-term use appears safe. But for expectant or nursing moms, those with thyroid disorders, autoimmune disease, liver issues, or complex medication regimens, a doctor’s oversight is wise. Not because the herb is dangerous, but because it never hurts to be cautious! 

What About The Ashwaghanda In Magnesium Relax?

AlgaeCal chose to use Sensoril® in Magnesium Relax. In a market crowded with anonymous powders and vaguely described “blends”, Sensoril®  stands out as one of the better-studied forms of Ashwagandha available today, with more than a dozen clinical and preclinical studies⁷ behind it. In those trials, researchers didn’t just ask people how they felt; they tracked stress scores, sleep quality and key blood markers, and kept a careful log of anything that might hint at trouble. The pattern that emerged was reassuringly consistent: meaningful improvements in how people coped with stress, and no serious safety concerns. In other words, the version of Ashwagandha inside Magnesium Relax isn’t there because it’s fashionable, but because it’s one of the few that has actually earned its place in the scientific literature.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

‡Results consistent with Clinical Trials. Results may vary.

†Open to US customers only.