Choosing the Right Hair Supplement: A Trichologist's Guide
By Sofia Baig, Lead Trichologist at Monpure London
Stand in the supplements aisle of any pharmacy, or scroll a wellness site for five minutes, and the hair category alone can leave you feeling overwhelmed. There are a lot of products. The claims are loud. And if you are dealing with thinning, more shedding than usual, or you simply want to look after your hair for the long term, it is genuinely hard to know where to begin.
These are the questions I hear most from the clients I see in my clinic. So here, from all my learnings over years of testing and reviewing them, is how hair supplements actually work, what is worth looking for, and how to think about taking them in a way that suits you.
Start with the why, not the bottle
Before you reach for anything, it helps to understand why your hair is behaving the way it is. Thinning and loss have many possible causes. Nutrition plays a part, but so do hormones, stress, lifestyle changes, and a number of underlying medical conditions. The approach that works best almost always starts with finding the cause rather than guessing at a fix.
So my first piece of advice is usually the least glamorous: book a blood test. Ask your GP to look at your iron status, including ferritin, which tells you how much iron your body has in reserve. It is worth checking vitamin D, zinc, your B vitamins and thyroid function, too. These are the markers most often examined when someone is shedding or thinning, and a problem in any one of them can show up in the hair growth cycle. Where there is a genuine deficiency or imbalance, treating it directly tends to be the most effective thing you can do.
One practical note. If you already take a supplement containing biotin, or you are about to start one, tell your GP before any blood test. Biotin in the bloodstream can skew certain results, so it is worth mentioning in advance.
Do hair supplements actually work?
Yes, with two conditions: the formula has to be right, and it has to be meeting a real nutritional need. That second part matters. A supplement is not a universal answer to every kind of hair loss. It works best when it is filling a genuine gap.
It helps to know how demanding hair follicles are. They are among the busiest structures in the body, dividing rapidly and needing a steady supply of nutrients to build keratin and keep the active growth phase, the anagen phase, going. When nutrition falls short, whether through diet, long periods of stress, or hormonal change, the follicle is one of the first things the body is willing to deprioritise. It will look after your heart and brain long before it worries about your hair.
A good supplement closes those gaps from the inside. It will not push your hair to grow faster than its natural cycle allows, and it will not deliver results overnight. What it can do is support the conditions your follicles need to do their job well over time.
What makes a formula worth taking
Not every supplement is equal, and I am considered about what I will recommend.
The nutrients most associated with healthy growth are iron, vitamin D, zinc, biotin and several of the B vitamins. Ferritin, again, is worth keeping in mind, since iron stores come up so often when we investigate hair concerns. A formula worth your money should contain meaningful amounts of these and be designed to top up your diet where it falls short. The right levels for you depend on your own needs and where your nutrition currently sits.
More is not automatically better, though. Biotin is in almost every hair supplement on the shelf, yet a true biotin deficiency is fairly uncommon. Supplementing helps most when there is an actual shortfall to address.
Two other things I look at. The first is bioavailability, which is simply how well your body can absorb and use each nutrient. A number on the label means little if it never reaches the follicle. The second is what else is in the capsule. Some ingredients are there for good reason, to keep the product stable and consistent, but a well-made formula keeps the active ingredients front and centre and leaves out the filler it does not need.
How long before I see results?
This is the question I am asked most, and the one where I am most careful to be honest.
Hair grows slowly, somewhere around one to one-and-a-quarter centimetres a month, and even that varies with age, genetics and general health. Supplements have to work at the pace of your hair cycle. They cannot override it. Some people notice early changes after roughly eight to twelve weeks of taking a supplement consistently. The results that actually matter, better density, better quality, hair that simply feels in better condition, usually show up around the three to six month mark.
I always frame this as a hair longevity journey rather than a quick fix. When the changes come, they are worth the wait.
Can supplements help with hair loss and thinning?
They can. But I would always describe them as a support, not a replacement for proper medical assessment where something underlying might be driving the loss.
Supplements earn their place when a nutritional deficiency or shortfall is part of the picture, which happens more often than people expect. Stress, hormonal shifts, the postpartum months and restrictive diets can all drain the very nutrients follicles rely on. Where thinning has a nutritional element, the right supplement can support the environment your hair needs to grow well over time.
That said, if your hair loss is significant or comes on suddenly, please get a professional assessment first. Working out what is actually causing the change is always the most important step.
A word on postpartum hair loss
Postpartum shedding is one of the most common things I see, and one of the most upsetting, partly because it can feel so sudden and so dramatic.
The clinical name is telogen effluvium, and it is set off by the hormonal shift after birth. Through pregnancy, higher oestrogen keeps more of your hair in its growth phase for longer. Once levels fall after the birth, a large share of hairs move into the resting and shedding phase together. For most women it becomes noticeable around two to four months in.
Here is the reassuring part. It usually settles within six to twelve months, as hormones rebalance and the cycle finds its rhythm again. Nutrition can genuinely help the recovery, because pregnancy and breastfeeding draw heavily on the nutrients the follicle needs most.
My most important advice to any new mum, though, is to speak to your doctor first. Not only about your hair, but to make sure you are well and properly supported through the whole postnatal period. Hair health reflects whole-body health, and good medical guidance is always the right foundation to build on.
The one I recommend
For a daily supplement that ticks the boxes I look for as a trichologist, I recommend the Monpure Hair Longevity Supplement. It brings together twelve vitamins and minerals in a considered blend made to support healthy growth and overall hair quality, with bioavailability and a clean, filler-free formulation at its core.
Taken consistently, as one part of a thoughtful approach to your hair, it lines up closely with what I look for when I assess a supplement.
The bottom line
Hair supplements can be a real asset. They just work best when you choose them carefully, base the choice on your own nutritional needs, and pair them with a wider commitment to your hair and your health.
Start with a blood test. Pick a formula built around bioavailability and meaningful nutrient levels. Then give it time. Your hair is worth the investment.
