what is the best supplement to lower cortisol

May 27, 2025

Medically Reviewed by By Girish Desai, the Chief Pharmacist at Landys Chemist since 1982

Written by Rhysa Phommachanh Head of Digital Marketing

What is the best supplement to reduce cortisol?

Cortisol is the body’s primary stress hormone, released by the adrenal glands in response to physical or emotional stress. The best supplements to reduce cortisol are ashwagandha and magnesium, both of which are backed by research for supporting the nervous system and regulating the stress response. Other effective options include omega-3 fatty acids, L-theanine, rhodiola rosea, phosphatidylserine, vitamin C, and probiotics. Each of these supplements works through a slightly different pathway, and may be used individually or in combination to support stress recovery and hormonal balance.

best supplements for high cortisol

Ashwagandha

Ashwagandha is an adaptogenic herb that helps regulate cortisol by supporting the HPA axis. Studies show it can reduce cortisol levels by up to 30% in people experiencing chronic stress. Living Nutrition Organic Fermented Ashwagandha Capsules offer a highly absorbable form — fermentation naturally enhances the uptake of active compounds like withanolides, making them more effective and gentle on digestion.

Magnesium

Magnesium plays a key role in calming the nervous system and supporting the production of GABA, the brain’s primary relaxing neurotransmitter. Clinical reviews suggest magnesium deficiency is common among people with high stress, and supplementation can improve stress tolerance and sleep quality. Magnesium glycinate is particularly well suited for relaxation due to its excellent absorption and gentle effect on the gut.

Omega-3 Fatty Acids

Omega-3 fatty acids - especially EPA and DHA, help regulate inflammation and support brain health, both of which influence cortisol output. Research shows omega-3 supplementation may reduce cortisol reactivity to mental stress while improving mood and cognitive function. These fats are commonly found in fish oil and algae-based supplements.

L-Theanine

L-theanine, found in green tea, promotes calm by increasing alpha brain wave activity and reducing excitatory signals. It is often used to manage performance-related stress or anxiety without causing drowsiness. Studies have shown that l-theanine can reduce salivary cortisol and promote a more relaxed mental state in stressful situations.

Rhodiola Rosea

Rhodiola is an adaptogen that helps reduce fatigue and restore energy balance during periods of high stress. It has been shown to support cortisol regulation and improve mental performance. Living Nutrition Organic Fermented Rhodiola Capsules are an ideal option, as fermentation enhances bioavailability and supports gut health, making the adaptogens more effective and easier to tolerate.

Phosphatidylserine (PS)

Phosphatidylserine is a phospholipid found in brain tissue that plays a role in regulating the body's stress response. Clinical research shows PS can reduce cortisol spikes triggered by intense physical activity or prolonged mental stress. It is particularly useful for those experiencing brain fog, burnout or cognitive fatigue.

Vitamin C

Vitamin C is essential for adrenal function and antioxidant defence. During stress, it is rapidly depleted, which may impair cortisol regulation. Studies show that supplementing with vitamin C can help lower cortisol responses to physical and psychological stress. One study found that 1,000mg per day significantly reduced post-stress cortisol levels and improved overall mood.

Probiotics

Probiotics help balance the gut-brain axis, a critical pathway in cortisol regulation. Clinical research has shown that certain strains - such as Lactobacillus helveticus R0052 and Bifidobacterium longum R0175, can reduce salivary cortisol and psychological distress. A trial in the British Journal of Nutrition found significant cortisol reduction in adults taking these strains daily, suggesting a role for probiotics in stress management and emotional resilience.

Can you take these supplements together?

Yes. Combining cortisol-lowering supplements can improve results, as each targets a different part of the stress response. Clinical reviews and practitioner experience suggest that multi-nutrient approaches offer broader support for adrenal function, cortisol regulation, and emotional resilience

Ashwagandha + Magnesium: Supports both hormone balance and nervous system calm
Omega-3s + Phosphatidylserine: Helps reduce inflammation and mental fatigue
Rhodiola + L-Theanine: Boosts energy and focus without overstimulation
Probiotics + Vitamin C: Strengthens gut-brain and immune support for resilience

Shop through our range of supplements to regulate your cortisol response today.

Final Thoughts

If you’re searching for the best supplement to reduce cortisol, focus on what addresses your personal stress triggers. Supplements like ashwagandha and magnesium are widely recommended for cortisol regulation, but the most effective approach often combines targeted nutrients that support mood, sleep, and brain resilience. Those with anxiety may benefit from L-theanine or probiotics, while physical burnout might respond better to adaptogens like rhodiola or phosphatidylserine. Combining two or more of these can support a balanced stress response.

“In the pharmacy, we often see that cortisol imbalance presents differently for everyone - from fatigue and low mood to disrupted sleep or poor gut health. The key isn’t just finding one supplement, but identifying which system needs the most support. For some, that might be magnesium for nervous tension; for others, it’s probiotics for gut-brain balance. Food-grade botanicals, especially those that are fermented can offer gentle but effective long-term results.” – Girish Desai, Pharmacist at Landys Chemist