Niacinamide Serum for Men: Benefits, How to Use It and How Long It Takes

What a niacinamide serum does for oily, mark-prone men's skin, how to use it morning and night, and how many weeks the trials say it takes to work.

By Abhishek Jain 23 Sep 202611 min read

Illustration of a young Indian man at a washbasin, a scooter helmet on the shelf beside him, holding a glass dropper with clear serum drops on his fingertips

A niacinamide serum helps men's skin make less oil, makes pores look smaller, and helps fade the dark marks that pimples leave behind. Use 3 to 5 drops on a clean face once or twice a day, under moisturizer, with sunscreen in the morning. Oil drops within 2 to 4 weeks. Pores and marks take 8 to 12 weeks.

It is 4 pm in the office washroom. The mirror is honest. Your forehead has a shine that was not there at 9 am, and the mark from last month's pimple is still on your cheek, like it pays rent.

You wash your face. Ten minutes later, the shine is back. This is the daily loop for most men in Indian cities: oil, wash, oil.

So you search "niacinamide serum for men" and get 40 bottles, six percentages and a fight about morning versus night. Here is the short answer.

Niacinamide is a form of vitamin B3. On skin, it helps cut oil, makes pores look smaller, and helps fade dark marks.
Yes, men can use it. Men's skin makes more oil, so it has more to work with.
Use 3 to 5 drops on a clean face, morning, night, or both. Moisturizer on top. Sunscreen in the morning.
Less shine in 2 to 4 weeks. Pores and marks take 8 to 12 weeks.

Now the detail, and the proof.

Why Do Men Get Oily Skin and Dark Marks?

Every hair on your face has a small oil gland attached to it. The gland pumps oil (sebum) up the pore to keep the skin soft. Think of each gland as a tap. In a lot of men, the taps run too far open.

A review of 57 studies found that men's skin makes more oil than women's, and is thicker too. Add a Mumbai afternoon in May, a helmet and a two-hour commute, and the shine takes care of itself.

Oil is also where a pimple starts. When it mixes with dead skin and clogs a pore, you get a blackhead or a bump. When the bump heals, Indian skin does one more thing. It leaves a dark mark.

The mark has a name: post-inflammatory hyperpigmentation, or PIH. A review of PIH in skin of colour says it hits darker skin more often, and worse. A Singapore study in that review found it more common in Malays and Indians than in Chinese patients. Untreated, a mark can take months to years to fade, and sun makes it darker.

So oil, pores and marks are one linked problem, not three. That is why the oil control range is built around one active that works on all of them.

Labelled cross-section diagram of human skin showing the epidermis, dermis, a hair follicle and the sebaceous gland attached to it — The sebaceous gland, top left, is the oil tap. It sits on the hair follicle and empties into the pore, which is why the shine and the pimple share an address. (Photo Credit: BruceBlaus, Wikimedia Commons, CC BY 3.0)

What Does Niacinamide Do for Men's Skin?

Niacinamide is a form of vitamin B3. It dissolves in water, sits well in a light serum, and is one of the best-studied actives in skincare. Medical papers call it nicotinamide. Same molecule.

Less oil. In a trial of 100 Japanese volunteers, 2% niacinamide cut oil output at 2 and 4 weeks compared with a placebo. A 2024 review found the same in several trials at 2% to 5%, in Asian and white volunteers. An Indian review in IJDVL adds a 160-patient trial. In it, 4% nicotinamide gel beat an antibiotic gel on oiliness scores.

Smaller-looking pores. In 52 Taiwanese volunteers, 4% niacinamide cut pore counts by week 8. Skin looked more even too.

Fewer dark marks. Niacinamide does not stop skin from making pigment. It blocks the hand-over. One cell makes pigment and passes it to the cells around it. A 2002 trial found niacinamide cut that hand-over by 35 to 68% in the lab. In the same paper, Japanese women on 5% had fewer dark marks after 4 weeks. In 50 white women, 5% niacinamide twice a day for 12 weeks reduced dark spots, red blotches and fine lines.

A stronger barrier. Niacinamide pushes skin to make more ceramides, the fats that hold the top layer together. A 2000 study found it raised ceramide production in skin cells 4 to 5 times over, and cut water loss on dry skin. That is why it can control oil without leaving your face tight.

Calmer pimples. Acne is a medical condition, so this part is about the molecule, not any product. In a 76-patient trial, 4% nicotinamide gel matched 1% clindamycin, an antibiotic gel. Over 8 weeks, 82% improved versus 68%. An 80-patient trial in Iran found nicotinamide gel worked better on oily skin types.

Now to the bottle. THERŌ's niacinamide serum for oily skin carries 5% niacinamide, the top of the range the trials above used. It adds salicylic acid, which gets inside the pore and clears buildup. Then mandelic acid, the mildest AHA, and green tea. It helps control excess oil, refine the look of pores, and reduce the appearance of post-acne marks. In the 60-day consumer study on the product page, 95% of users noticed visibly reduced spots. That is what users reported, not a clinical trial.

THERŌ Active Oil Control Niacinamide Serum in an amber dropper bottle, caught in a splash of water with green tea leaves — 5% niacinamide, salicylic acid, mandelic acid and green tea in a 30 ml dropper bottle. The liquid is clear and water-light, which matters when it is 34°C outside. (Image: THERŌ)

How to Use Niacinamide Serum: A Simple Routine for Men

Four steps. Two minutes. No 10-step routine.

Morning

Cleanse. Wash with a face wash made for oily skin. Lukewarm water. Pat dry.
Treat. Put 3 to 5 drops of niacinamide serum on your face and neck. Pat it in. Give it a minute.
Moisturise. Use a light moisturizer that will not clog pores. Yes, even on oily skin.
Protect. Sunscreen, SPF 30 or higher. Two finger-lengths for the face and neck. The PIH review above puts daily SPF 30 at the base of any dark-mark plan.

Night

Same three steps, minus the sunscreen. If you are new to actives, start with once a day, at night, for a week. Then go twice a day if your skin is happy.

Three rules that keep it simple:

Clean face first. Serum on top of sweat and dust does nothing for you.
Patch test on the jaw for two nights before the first full use.
Do not start a new acid, a retinol and this serum on the same day. One new thing at a time.

If your commute is the main event of your day, a moisturizer with DustShield™ against PM2.5 earns its place in step 3. The rest of the four-step logic is in Skincare Routine for Men: A Simple 4-Step Guide for Indian Skin.

Illustration of an Indian man at a desk at night holding a glass dropper over clear serum drops on his fingertips, with a table lamp, laptop and cricket bat behind him — Three drops, pat, done. The night version of the routine is the morning one without sunscreen, which is the only step you are allowed to skip. (AI-generated image)

Niacinamide Mistakes and Myths (India Edition)

"Oily skin does not need moisturizer." Skip it and the skin loses water, which many men read as a sign to wash more. A moisturizer for oily skin is light, not greasy. Niacinamide itself builds the barrier, remember.

"Wash five times a day and the oil goes." Washing removes the oil on top. It does not touch the tap. Twice a day with a face wash, and a splash of water in between if you must.

"Never mix niacinamide with vitamin C." This one refuses to die. The PIH review says light, moisture, acids and alkalis do not affect niacinamide. An Indian review of vitamin C says vitamin C can be used with other antioxidants and acids. THERŌ's own vitamin C serum has niacinamide in the formula. Use them together, or split them: vitamin C in the morning, niacinamide at night. The full argument is in Vitamin C or Niacinamide: Which Serum Should Men Start With?.

"More percent, faster results." The trials above worked at 2% to 5%. The 2024 review reports no irritation up to 5% and no stinging up to 10%. Above that, you are paying for a bigger number, not a better face.

"A cream from the chemist will fix the marks faster." Many of those tubes are steroid creams. A study across 12 Indian dermatology centres found 14.8% of patients with face problems were using one. Many used it as a fairness or general cream. And 90.5% of them had side effects, with acne the most common. Do not use a steroid cream on your face without a prescription, and skip anything sold as a fairness cream.

How Long Does Niacinamide Serum Take to Work?

"Niacinamide serum kitne din mein asar dikhata hai" is a real search in India. Here is a real answer, from the trials.

Less oil, less shine: 2 to 4 weeks. That is when 2% cut oil output in 100 Japanese volunteers.
Smaller-looking pores: 8 weeks. That is when 4% cut pore counts in 52 Taiwanese volunteers.
Fewer dark marks: 4 to 12 weeks. That is the range in which 5% reduced dark spots in Japanese women and in 50 white women.

Two honest notes. Most of this research used East Asian or white skin. The PIH review says no trial has tested niacinamide alone on dark marks in darker skin. The trials that exist point the same way, but keep your expectations at "better", not "gone".

Use it every day and take a photo in the same light on day 1. You will not notice the change in the mirror. The photo will. If you are still choosing a bottle, the serum collection has one for oil and one for tan.

When Should You See a Dermatologist?

Painful, deep or cystic pimples, or pimples that leave pits.
A dark patch that is spreading, or appeared out of nowhere.
Itchy red rings or spots on the face, jaw or neck. In humid weather, fungal infections often get mistaken for acne.
Burning, peeling or a rash after a new product that lasts more than a day or two.
No change after 12 weeks of daily use.

And never a steroid cream, or a fairness cream, on your own.

Niacinamide for Men: Common Questions

Can men use niacinamide serum?

Yes. Niacinamide works on oil, pores and marks, not on gender. Men's skin makes more oil, is thicker, and marks easily, so there is more for it to do. A niacinamide serum made for men's skin is the same molecule in a formula built for thicker, oilier skin.

Can I use niacinamide every day? What happens if I use it daily?

Daily is how the trials used it, once or twice a day for 4 to 12 weeks. Nothing bad happens. That is the point. Skipping days is what slows results.

Who should avoid niacinamide serum?

Almost nobody. Clinical tests found no irritation up to 5%. If your skin is reactive, or you have a rash, eczema or a face-wide breakout, patch test first and ask a dermatologist. If a product stings and stays red, stop.

Does niacinamide brighten skin?

It evens tone. By blocking the pigment hand-over, it helps fade tan and dark marks, so skin looks brighter and more even. It does not change your natural skin colour, and no honest product will. For tan and dullness as the main worry, brightening is the vitamin C range's job.

Can I leave serum on overnight?

Yes. Serum is not a mask. Apply at night, add moisturizer, sleep. Niacinamide is stable in light and air, so the morning works too.

Which serum is best for men, vitamin C or niacinamide?

Oily skin, pimples, open pores, marks: start with niacinamide. Tan, dullness, sun damage: start with vitamin C. The two do not fight, so you can run both.

So, Should Men Use a Niacinamide Serum?

If your problems are oil, open pores and the marks pimples leave behind, yes. It is one of the best-tested actives in skincare. The trials worked at 2% to 5%. THERŌ's Active Oil Control Niacinamide Serum sits at 5%.

Tonight: wash, 3 to 5 drops, moisturise. Tomorrow morning: the same, plus sunscreen. Photo on day 1, photo on day 30.

If you want the full set, the Active Oil Control range is three steps, not ten. The bestsellers page shows where most men start.