At one point in life, your hair may have been one of your favorite physical features—but with aging or menopause, it can suddenly feel unfamiliar. Whether it's dull, brittle, harder to detangle or shedding more than usual , these changes can be frustrating. The good news? A sea-based ingredient called red algae is making waves in hair health research, and doctors say it could help restore the shine and strength you've been missing. We looked at new research on red algae benefits for hair and spoke with doctors about how it works. Plus get insight into other standout ingredients and supplements that can help.
New research on red algae benefits for hair
If you’ve noticed more hair loss lately, you’re far from the only one. A survey from GenM and Schwarzkopf found that 35 percent of women ages 45 to 55 experienced hair thinning , 30 percent noticed less shine and 26 percent reported increased brittleness since entering menopause. Enter red algae.
“Red algae (Kappaphycus alvarezii) is a marine plant rich in natural biopolymers that can coat the hair strand, seal in moisture and shield it from environmental damage like heat,” explains Michelle Seguin, MD , Physician at Root Functional Medicine.
Her Hair Was Falling Out in Clumps—Until Sea Kelp Sparked New Growth
And early research confirms its potential benefits for promoting healthy hair. In a lab study published in ACS Omega , hair fibers treated with topical red algae and tara extract—a Latin American shrub whose fruit contains moisturizing compounds—appeared shinier, smoother and easier to comb . As a result, you may experience less breakage when brushing that can make your strands appear fuller rather than sparse.
Here’s why it works: “The biopolymer molecules form a durable film along the hair shaft by interacting with keratin, the structural protein that makes up hair,” says Dr. Seguin. “That film physically smooths the outer cuticle layer, which reflects more light (shine), reduces friction between strands (easier combing) and seals in moisture (smoothness).”
How to get the benefits of red algae for healthier hair
To maximize the benefits of red algae for stronger, healthier hair, you’ll want to apply the extract topically rather than taking it as an oral supplement. That means looking for shampoos, conditions or leave-in treatments that list red algae as an ingredient.
“ While red algae can help provide iodine and trace minerals that promote overall health, we do not have strong evidence that taking the product orally will help promote hair shine and texture as the topical does,” says Farhan Abdullah, DO , a board-certified internal medicine physician and the medical director of Magnolia Functional Wellness in Southlake, Texas. “The appearance of the hair shaft is generally determined by external conditioning rather than internal supplementation.”
Red algae is generally well tolerated when used topically on your hair and scalp, but Dr. Seguin recommends anyone with a sensitive scalp do a patch test before use. Two options to consider: Eva NYC Repair Ritual Strength Shampoo and Moroccanoil Hydrating Conditioner , both with red algae.
4 hair supplements that promote healthy growth
While red algae is best used as a topical hair product, there are supplements you can add to your health routine to promote hair growth and strengthen hair naturally. Here are four recommendations from our experts:
Biotin
Dr. Seguin and Dr. Abdullah both say biotin supports keratin production, which is key for healthy hair growth. A typical dose ranges from about 2.5 mg to 5 mg daily. Dr. Seguin adds that deficiency is linked to shedding and thinning, but notes that high doses above 10 mg can cause toxicity and interfere with lab tests, so it’s important to notify your doctor before bloodwork.
Iron
An iron deficiency is a common and often overlooked cause of hair loss. Dr. Abdullah says typical dosing ranges from 18 mg to 65 mg daily. Worth noting: Dr. Seguin adds that you should check your iron levels before adding iron to your routine, as unnecessary supplementing can cause unwanted GI side effects or even toxicity.
How Fast Does Hair Grow — And Are There Ways To Make Thinning Hair Grow Faster (And Fuller)?
Collagen peptides
Our experts agree that collagen peptides provide amino acids needed for supporting keratin and supporting overall hair structure. Dr. Seguin adds that collagen also supports the connective tissue around hair follicles, which can thin with age. She suggests doses ranging from about 2.5 grams to 10 grams daily.
Vitamin D
Dr. Abdullah explains that vitamin D supports the hair growth cycle and immune function. He recommends a daily intake of 1,000 IU to 2,000 IU.
The bottom line on red algae and other hair growth supplements
The journey to healthier hair is individual, and what works for one person may not be right for another. The key is staying informed about new research, listening to your body and working with your doctor to find the right combination of topical treatments and supplements.
Ready for more inspiration? Subscribe to our YouTube channel for video podcasts, health tips and uplifting stories designed for women 40, 50, 60 and beyond.
Keep scrolling for more health stories!
5 Supplements for Arthritis That Ease Pain and Stiffness Naturally—Plus 1 You Can Skip
Do Vitamin Patches Work? Doctors Reveal the Truth About the TikTok Wellness Trend for Women 50+
The Best Fish Oil at Costco for Better Heart Health (That Doesn’t Hurt Your Wallet)
This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan .
