My short answer is that serums and supplements work in different ways, so it's hard to say that one helps more than the other. A serum works at the scalp, where it stimulates the follicle directly. A supplement works from the inside. It supplies nutrients the follicle needs, and when it contains DHT blockers such as saw palmetto, pygeum or pumpkin seed oil, it acts on the hormone behind pattern hair loss. Because they work in different ways, the two don't compete. For most people with pattern hair loss, the best approach is to combine them, preferably together with the right shampoo and oral collagen peptides.

I should be upfront that MDhair sells both serums and supplements, so I have no reason to talk you out of either. Most of what you'll read on this question comes from companies that sell only one of the two.

Why this is harder to answer than it sounds

Nobody has run the trial the question seems to ask for, where one group uses "a serum" and another takes "supplements" and researchers compare the two. Part of the reason is that neither word means one thing. A serum on a store shelf could be minoxidil, an FDA-approved drug, or a rosemary-and-caffeine blend tested in one small trial. The supplement aisle runs from single vitamins to plant formulas that act on hormones. So the question has to be answered piece by piece. What has each kind of product shown on its own? Has anyone compared the two routes directly, even in a narrower way? And what happens when they're combined?

What topical serums have shown

Minoxidil sits at the top of the topical evidence. It's one of only two drugs the FDA has approved for pattern hair loss, sold over the counter at 2% for women and 5% for men, and decades of trials back it. Anything else marketed as a hair growth serum is a cosmetic, which means it hasn't been through that approval process. Some cosmetic ingredients have been tested seriously, though.

Yunes Panahi's group in Tehran ran one of the few direct comparisons in 2015. They took 100 men with pattern hair loss and split them evenly, half applying rosemary oil and half 2% minoxidil, for six months. Three months in, there was little to show in either group. By six months, both had gained hair, and the difference between them wasn't statistically significant. The rosemary group also reported less scalp itching. It's one trial, against the lower strength of minoxidil, and it hasn't been widely repeated, but it's a real head-to-head result.

Caffeine has a similar story. A 2017 multicenter study in India gave about 200 men either a caffeine-based liquid at 0.2% or 5% minoxidil, and found the caffeine product wasn't meaningfully worse over six months. That was an open-label study funded by the caffeine product's maker, which is worth weighing.

The practical limit with any serum is the daily routine. Topicals work only where they're applied and only as long as you keep applying them, and missed weeks show up in the results. A product that's sitting in the bathroom cabinet doesn't do anything, whatever its trial data looks like.

What supplements have shown

In 2022, dermatologists at Brigham and Women's Hospital in Boston set out to see what the evidence for hair supplements actually amounted to, and published the answer in JAMA Dermatology. Their search turned up more than 6,300 citations, and once they'd set aside studies of people with known deficiencies, 30 were left. Seventeen were randomized trials.

Their findings were more encouraging than the authors expected going in. Twelve of the 20 products and ingredients they evaluated had higher-quality studies suggesting some benefit, including several branded formulas and single ingredients like pumpkin seed oil and zinc. The caveats were substantial, though. Many studies were small, and some were funded by the companies selling the products. The senior author, Arash Mostaghimi, said in an interview afterward that the data weren't strong enough to say any one supplement beats another, and that none of it approaches the rigor behind an FDA-approved medication.

Supplements fall into two groups, and they work in different ways.

The first group is DHT blockers. Pattern hair loss is driven largely by dihydrotestosterone (DHT), a hormone that gradually shrinks genetically sensitive follicles. Finasteride, the other FDA-approved drug, works by blocking the enzyme that makes DHT. Several plant ingredients appear to act on that same enzyme more gently, saw palmetto, pygeum and pumpkin seed oil among them. That makes them relevant to pattern hair loss itself, not only to nutrition. In a 2014 Korean trial, 76 men with pattern loss took pumpkin seed oil capsules or a placebo for 24 weeks. Hair counts rose about 40% in the pumpkin seed group, against about 10% on placebo. A 2020 systematic review of saw palmetto in hair loss found improvements in hair count, density or overall hair quality across most of the studies it included. Both oral and topical forms showed benefit. None of this puts these botanicals on par with finasteride. But for someone with pattern hair loss, a supplement with DHT blockers is a reasonable way to support hair growth, and it acts on something a topical like minoxidil doesn't.

The second group is vitamins and minerals, and here a point gets lost in supplement marketing. A 2019 review in Dermatology and Therapy from Antonella Tosti's hair research group in Miami came to a conclusion supplement labels rarely mention: vitamins and minerals help most clearly when someone is low in them to begin with, with iron as the usual example. Topping up a nutrient you already have enough of has far less behind it. That's why I'd rather see a blood test than guess, especially after a stretch of hard dieting.

Testing the two routes against each other

The nearest anyone has come to testing the two routes against each other was a 2023 trial in Bengaluru, India, published in Clinical, Cosmetic and Investigational Dermatology. Its 80 volunteers all had mild-to-moderate pattern loss. They got the same saw palmetto extract in one of two forms, a daily capsule or a scalp lotion, and each form had its own placebo group. By week 16 both forms had beaten their placebos. The capsule cut hair fall by up to 29%, while the lotion produced the larger gain in density, about 7.6%. Each arm was compared with its own placebo rather than with the other, so it doesn't crown a winner. That's the point. Even with the same active ingredient, the oral and topical routes helped in different ways, one mainly by reducing shedding and the other mainly by adding density. That is why it's hard to rank a serum against a supplement, and why using both makes more sense than choosing one.

Combination evidence is thinner, and most of it comes from drugs rather than from serums and supplements. A 2015 randomized study of 450 men in China compared oral finasteride, topical minoxidil, and the two together over a year. By the end, 94.1% of the men on the combination had improved, against 80.5% on finasteride alone and 59% on minoxidil alone. Those are drugs rather than cosmetics, so I wouldn't carry the numbers over to serums and supplements. What I would carry over is the reasoning. That trial paired an oral DHT blocker with a topical growth stimulant, and the two working by different routes added to each other. A supplement with DHT-blocking botanicals plus a topical serum follows the same logic, at a gentler level.

My team and I tested that idea in our own six-month clinical trial, published in the Journal of Drugs in Dermatology in 2025. MDhair's regimen combines topical products with supplements, personalized to each person. We compared it with one specific competitor, the leading hair loss supplement brand. That design is close to the question in this article's title, though it can't separate how much of the difference came from the topicals, the personalization, or the specific ingredients. With that caveat in mind, at 90 days hair growth had improved about 2.8 times as much as with the supplement alone. For hair quality the figure was about 3.0 times.

Why the shampoo and collagen peptides belong in the plan

A serum and a supplement cover the follicle from the outside and from the inside. Two more steps round that out. The right shampoo keeps the scalp clean and calm. It clears away oil and buildup that can irritate the scalp and get in the way of a topical, and it doesn't strip hair that's already thinning or fragile. Oral collagen peptides supply amino acids and supporting nutrients the body uses to build hair and the skin around the follicle. The research on shampoos and collagen peptides for hair is earlier and smaller than for minoxidil or saw palmetto. I see them as supporting the main treatments, not replacing them. But they cost little effort, and together they make the regimen complete.

How long before you can judge either one

The rosemary trial is a useful guide here. At three months, neither the rosemary group nor the minoxidil group had gained much, and the people in it could easily have concluded that nothing was working. The improvement showed up between months three and six. Most of the supplement studies in the 2022 review ran for somewhere between three and six months too, and DHT-blocking botanicals in particular tend to need several months before a difference is visible.

I'd give whatever you choose four to six months, partly because a follicle that does respond still has to grow a new hair at about a centimeter a month. A photo of your part or crown taken on day one makes the comparison honest later.

What to watch for when you start

Some people starting minoxidil see more hair in the drain for the first few weeks. The drug nudges resting follicles into a new growth cycle, and the old hairs make way. It usually calms down within a couple of months, which is easier to sit through if you know it's coming.

Turn a hair supplement bottle around and you'll often find several thousand micrograms of biotin per serving, against the roughly 30 micrograms adults need. The FDA warned in 2019 that doses like that can throw off some lab tests, including thyroid tests, so if yours has biotin, mention it before any blood draw.

So which works better, a serum or a supplement? On the evidence as it stands, I don't think that question has a clean answer. They act on different parts of the problem. A serum stimulates the follicle at the scalp. A supplement with DHT blockers acts on the hormonal driver of pattern hair loss and fills any nutritional gaps. For most people with pattern loss, the most effective approach is to combine them, preferably with the right shampoo and oral collagen peptides. The honest qualification is that the case for combining them rests on different mechanisms and our own trial, more than on a large independent study of this exact combination.

Matching the approach to the situation

Someone who's been shedding heavily since a crash diet, or who has heavy periods and feels run down, probably needs to start with blood work. If iron or vitamin D comes back low, treating that is the first step, and a supplement may be part of the answer for a while.

A woman in her 40s whose part has been widening slowly over a few years is in a different position. That's the classic pattern picture, and I'd want the full combination from the beginning. That means a topical (minoxidil if she's comfortable with it), a supplement with DHT-blocking botanicals, a suitable shampoo, and collagen peptides.

Then there's the person who knows they won't keep up a daily scalp routine. For them, a supplement they'll actually take may do more in practice than a serum they'll abandon by week three. For someone with pattern loss, I'd want that supplement to include DHT blockers rather than vitamins alone, and I'd keep encouraging the topical.

A man who's already on minoxidil and wonders whether a supplement would add anything is another common case. Minoxidil stimulates growth but does nothing about DHT, so a supplement with saw palmetto or pygeum adds a second mechanism instead of doubling up on the first. I'd still check whether he's applying the minoxidil every day, since consistency matters most. A hard diet or a low iron result would move treating the deficiency further up his list.

Minoxidil isn't recommended in pregnancy. Many DHT-blocking botanicals, saw palmetto among them, have hormonal activity that makes them a poor choice while pregnant or trying to conceive. That's a conversation for your doctor before starting anything.

Smooth bald patches are a different matter, and so is a scalp that itches, scales, or hurts. I'd want a dermatologist to see either before anyone reaches for a serum or a supplement.

Where MDhair fits

MDhair has two lines, and each is built around the combination approach. Each includes a serum, a shampoo, an oral supplement, and a marine collagen with hydrolyzed peptides, vitamin C and hyaluronic acid.

The Regrowth line is built for pattern hair loss. Regrowth Supplements bring the same approach to the oral side: they contain the DHT-blocking botanicals saw palmetto and pygeum, together with more than 20 vitamins and plant-based complexes, to help support hair growth in people with pattern hair loss.

The Restore line is aimed at damaged, breakage-prone hair. Restore Supplements focus on nutrient replenishment. Our OTC minoxidil ($24) is the medicated option.

Our customized kits combine a serum, a shampoo, an oral supplement and marine collagen peptides by design, for the reasons laid out above, starting with the Essential Regrowth Kit at $66.

A quick word on labels. Minoxidil is the one product we sell with OTC drug status, approved for mild-to-moderate androgenetic hair loss. Our serums and shampoos are sold as cosmetics and our supplements as dietary supplements. So none of them is meant to diagnose, treat, cure, or prevent disease, and the FDA hasn't reviewed what's claimed for the supplements. If you're pregnant or nursing, check with your doctor first, and stop any serum that irritates your scalp.

Which combination of serum, shampoo, supplement and collagen peptides makes sense for you depends on what's behind your hair loss, and our free AI hair and scalp assessment is designed to work that out. It starts with a short quiz about your hair history and a scalp photo, and every regimen includes unlimited chat access to our dermatologist team.

Dr. Yoram Harth is a board-certified dermatologist and Co-Founder and Chief Medical Officer of MDalgorithms Inc., the company behind MDhair and MDacne. A magna cum laude graduate of Tel Aviv University's Sackler School of Medicine, he trained in dermatology at Rambam Medical Center and completed a research fellowship at Columbia-Presbyterian Medical Center in New York. His work spans phototherapy, photodynamic therapy, and AI-personalized skin and hair care.

Sources

Studies were located through PubMed and the publishing journals' own sites.

1. Drake L, Reyes-Hadsall S, Martinez J, et al. Evaluation of the safety and effectiveness of nutritional supplements for treating hair loss: a systematic review. JAMA Dermatol. 2023;159(1):79-86. doi:10.1001/jamadermatol.2022.4867
2. Cho YH, Lee SY, Jeong DW, et al. Effect of pumpkin seed oil on hair growth in men with androgenetic alopecia: a randomized, double-blind, placebo-controlled trial. Evid Based Complement Alternat Med. 2014;2014:549721. doi:10.1155/2014/549721
3. Evron E, Juhasz M, Babadjouni A, Mesinkovska NA. Natural hair supplement: friend or foe? Saw palmetto, a systematic review in alopecia. Skin Appendage Disord. 2020;6(6):329-337. PubMed
4. Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A. The role of vitamins and minerals in hair loss: a review. Dermatol Ther (Heidelb). 2019;9(1):51-70. doi:10.1007/s13555-018-0278-6
5. Panahi Y, Taghizadeh M, Marzony ET, Sahebkar A. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed. 2015;13(1):15-21. PubMed
6. Dhurat R, Chitallia J, May TW, et al. An open-label randomized multicenter study assessing the noninferiority of a caffeine-based topical liquid 0.2% versus minoxidil 5% solution in male androgenetic alopecia. Skin Pharmacol Physiol. 2017;30(6):298-305. PubMed
7. Sudeep HV, Rashmi S, Jestin TV, Richards A, Gouthamchandra K, Shyamprasad K. Oral and topical administration of a standardized saw palmetto oil reduces hair fall and improves the hair growth in androgenetic alopecia subjects: a 16-week randomized, placebo-controlled study. Clin Cosmet Investig Dermatol. 2023;16:3251-3266. doi:10.2147/CCID.S435795
8. Hu R, Xu F, Sheng Y, et al. Combined treatment with oral finasteride and topical minoxidil in male androgenetic alopecia: a randomized and comparative study in Chinese patients. Dermatol Ther. 2015;28(5):303-308. PubMed
9. Bhardwaj V, Rodgers N, Harth O, Harth Y. Artificial intelligence-based personalization of treatment regimen for hair loss: a 6-month clinical trial. J Drugs Dermatol. 2025;24(3):233-238. doi:10.36849/JDD.8611
10. U.S. Food and Drug Administration. UPDATE: The FDA warns that biotin may interfere with lab tests: FDA safety communication. 2019. fda.gov

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