Throughout our 90-Day Hair Wellness® Reset, we’ve introduced you to several Practices that have the power to improve your hair over time. From gentle movement to stress management, these simple lifestyle shifts can lead to big changes — in not only your strands but your entire well-being.
With that being said, our final Practice focuses on how our immune system and hair growth are connected. In short, a well-supported immune system helps you stay strong, healthy and balanced by acting as your first line of defense against pathogens like germs and viruses. And when you’re healthy and functioning at one hundred, it creates the optimal environment for hair to thrive.
Research even confirms that immune cells — specifically regulatory T cells — directly activate hair follicle stem cells, making immune health one of the most overlooked factors in hair growth.
Now let’s dive into the nitty-gritty details — including easy, everyday ways to boost your immune health.
How Your Immune System Affects Hair Growth
How are immune health and hair loss related? Well, our immune system plays an important role in maintaining internal equilibrium, supporting processes like nutrient absorption and inflammation regulation — so if it becomes compromised, it impedes key functions that can eventually lead to thinning.
When your immune system is running smoothly, the body is better able to:
- Absorb key vitamins and minerals hair relies on
- Maintain a balanced scalp environment
- Respond to daily physical and environmental stress
In fact, a 2022 study published in Nature Immunology found that regulatory T cells communicate with hair follicle stem cells to trigger new hair growth — completely separate from their traditional immune function.
It’s also worth noting that because hair is not essential for survival, the body tends to prioritize vital organs when resources are limited. Case in point? If your immune system is weak and you’re constantly getting sick, your body will focus on fixing that instead of maintaining your hair health.
Daily Habits That Support Immune Health and Hair Growth
We’re not telling you to overhaul your whole lifestyle. The reality is: small, consistent healthy habits are what can help your immune health the most. Like these four:
- 🍊Eat immune-boosting foods. Vitamin C-rich foods like oranges, kiwis and strawberries are among the best foods for supporting hair growth and immune defense — they protect against oxidative stress that can disrupt the hair cycle.
- 🌙 Prioritize quality shut-eye. During sleep, the body restores and regulates key systems, including immunity. Most adults need 7 to 9 hours of sleep per night, as this gives the body time to repair and rebalance. Sleep deprivation has also been linked to increased cortisol, which can push hair follicles into a prolonged resting phase
- 🥣 Support your gut health. A large portion of the immune system is connected to the gut. Adding probiotic foods for hair growth support — like kefir, kimchi and yogurt — helps maintain a healthy gut-immunity balance.
- 🚫 Limit immune stressors. Excessive alcohol, ultra-processed foods and refined sugars can place extra strain on the immune system. Limiting these when possible can help support overall wellness.
The Reboot Challenge
When practiced consistently, small actions can help reinforce healthy routines. This week, try a simple daily step that supports immune health. Probiotic and fiber-rich foods are among the most studied dietary habits for gut health and immune support, both of which create the internal conditions hair needs to thrive.
For 7 days add one probiotic or fiber-rich food into your diet each day. Options might include:
- Yogurt or kefir
- Kimchi or sauerkraut
- Lentils or beans
- Whole grains or fiber-rich vegetables
These foods help support gut health, immune function, and nutrient absorption — all of which are important for the systems that support healthy hair.
Notice how these small additions fit into your routine. The goal isn’t perfection, it’s building habits for hair growth that feel sustainable.
Supporting Your Routine
Healthy habits form the foundation of Hair Wellness®, but in some cases, nutrient support can also play a complementary role. Our GRO+ Advanced Hair Growth & Density Supplements are designed to work alongside a balanced diet and lifestyle, helping support the body with targeted nutrients that contribute to overall Hair Wellness®.
They’re not meant to replace healthy routines, but they can help reinforce them.
As our series comes to an end, remember this: Small, daily wellness habits can help create the conditions for hair to remain strong and resilient long after the 90-Day Hair Wellness® Reset.
Frequently Asked Questions About Immune Health and Hair Growth
Does your immune system affect hair growth?
Yes. Research published in Nature Immunology found that immune cells called regulatory T cells directly activate hair follicle stem cells to trigger hair growth. When the immune system is under stress or weakened, this signaling breaks down, which can contribute to slower growth, increased shedding and a less resilient scalp environment.
Can a weak immune system cause hair loss?
It can contribute to it. When your immune system is compromised or under chronic stress, your body deprioritizes non-essential functions — and hair falls into that category. The body redirects resources toward vital organs, which can disrupt the hair growth cycle. This is separate from autoimmune conditions like alopecia areata, where the immune system actively attacks hair follicles.
Which foods support both immune health and hair growth?
Foods rich in Vitamin C (oranges, strawberries, kiwi), antioxidants (leafy greens, berries), and fermentables (yogurt, kefir, kimchi, sauerkraut) support immune function and the nutrient absorption your hair depends on. Zinc, iron, and biotin-rich foods also play a direct role in the hair growth cycle.
How does gut health affect hair growth?
A significant portion of the immune system lives in the gut. When gut health is compromised, nutrient absorption suffers — and hair is one of the first places that shows up. Supporting a healthy gut microbiome with fiber-rich foods and fermented options helps the body absorb the vitamins and minerals hair relies on, while also maintaining a balanced immune response.
Sources:
1. Cohen, Sandy. “If You Want to Boost Immunity, Look to the Gut.” UCLA Health, 19 Mar. 2021, www.uclahealth.org/news/article/want-to-boost-immunity-look-to-the-gut.
2. Cleveland Clinic. “Your Immune System: What You Need to Know.” Cleveland Clinic, 22 Dec. 2025, my.clevelandclinic.org/health/body/21196-immune-system.
3. Liu, Z., Hu, X., Liang, Y., et al. “Glucocorticoid Signaling and Regulatory T Cells Cooperate to Maintain the Hair-Follicle Stem-Cell Niche.” Nature Immunology, vol. 23, 2022, pp. 1086–1097. https://doi.org/10.1038/s41590-022-01244-9.
4. Munteanu, Camelia, and Betty Schwartz. “The Relationship between Nutrition and the Immune System.” Frontiers in Nutrition, vol. 9, 2022, pp. 1–23. www.ncbi.nlm.nih.gov/pmc/articles/PMC9772031/.
5. Salk Institute for Biological Studies. “Hair-Raising Research: Salk Scientists Find Surprising Link between Immune System and Hair Growth.” Salk Institute, 23 June 2022, www.salk.edu/news-release/hair-raising-research-salk-scientists-find-surprising-link-between-immune-system-hair-growth/.
