Instalab ResearchBefore reaching for a supplement, the strongest evidence supports lifestyle interventions: Sleep, stress management, and physical activity form the foundation of healthy cortisol regulation.
These should be the foundation, with supplements considered as a complement when additional support is needed. With that context in mind, let’s dive into what the research says about supplements that can help lower cortisol:
Cortitrol is a commercial blend designed to reduce stress responses. In a double-blind, placebo-controlled crossover trial, Cortitrol significantly lowered cortisol at rest and after resistance exercise, while also reducing markers of oxidative stress. This makes it one of the few supplements with repeated evidence of lowering cortisol in controlled human studies. For individuals undergoing physical stress, Cortitrol appears effective at moderating cortisol.
Cortislim is another marketed blend that has been studied in exercise settings. Research shows that it can blunt cortisol elevations during stress, but it does not appear to change fat oxidation, resting metabolism, or body composition. In other words, it may lower cortisol in the short term but does not necessarily produce downstream health benefits. Its effectiveness is modest compared to other options.
Fish oil, rich in omega-3 fatty acids like EPA and DHA, has some of the strongest evidence for cortisol reduction. In abstinent alcoholics, omega-3 supplementation lowered basal cortisol and reduced anxiety. In overweight adults, omega-3s reduced cortisol responses to acute social stress and dampened inflammation after several months of use. Omega-3s are therefore among the most reliable natural options for reducing stress-related cortisol elevations.
The gut-brain axis offers another avenue for cortisol regulation. A systematic review and meta-analysis of 46 randomized controlled trials found that probiotics lowered cortisol compared to placebo, though the effect was modest and somewhat inconsistent. Single-strain probiotics and interventions in healthy populations were more likely to show benefits. While probiotics do not have as large an effect as omega-3s, they appear to nudge cortisol in a favorable direction.
Tangeretin, a flavonoid from citrus peel, has been tested in athletes. In a randomized trial, four weeks of supplementation reduced cortisol and ACTH (a hormone that triggers cortisol release) after intense exercise, while also boosting antioxidant defenses. This suggests that plant bioactives like tangeretin can provide stress-buffering benefits in physically demanding contexts, though research is still limited.
Herbs such as Rhodiola rosea, Schisandra, and Eleutherococcus are often marketed as adaptogens. A trial in elite athletes using a blend of these adaptogens showed reduced cortisol and improvements in fatigue, focus, and performance. While promising, the research is limited and complicated by the use of blends, making it hard to pinpoint which herb drives the effect. Adaptogens may help, but evidence is less robust compared to omega-3s and probiotics.
Micronutrients like zinc and vitamin D have been tested in stressed and obese populations. A trial in individuals with depressive symptoms found that zinc and vitamin D supplementation improved mood but did not lower cortisol compared to placebo. In pregnant women, lipid-based supplements with vitamin D sometimes reduced cortisol late in pregnancy, but the effects were inconsistent. Overall, zinc and vitamin D support health in other ways, but do not reliably reduce cortisol.
HMB, a metabolite of leucine, has been explored for its potential to protect muscle during stress. One trial found that HMB altered cortisol awakening responses, showing reductions compared to placebo. The effects were modest, and there is little evidence connecting HMB supplementation with meaningful clinical outcomes related to stress or cortisol regulation.
Supplements can influence cortisol, but not all do so effectively. Cortitrol, omega-3 fatty acids, and probiotics have the most consistent evidence for lowering cortisol in humans. Tangeretin and adaptogenic blends also show promise, though more studies are needed.
Lowering cortisol is not about erasing it completely. Cortisol is essential for survival, metabolism, and immune function. The goal is to restore a healthy rhythm with peaks in the morning and declines at night. Anyone considering supplementation should see it as a complementary tool to normalize this balance, not replacements for foundational lifestyle habits.
