An asian man smiling and holding a jar of mood B complete vitamins


Wondering how long it’ll take for your B vitamins to kick in? Here’s what the science says

If you’ve been struggling with low energy, or are worried about a vitamin B12 deficiency, you may have heard about the benefits of supplementing with a B complex vitamin.

Now you might be wondering, ok, but how long does it take to start to feel the benefits of supplementing with B vitamins?

The short answer is, it depends! Read on to learn what factors impact how long it takes for B vitamin supplements to work, how you can speed up the process, and how you can expect to feel after 30, 60, 90 days and beyond!

The benefits of B vitamins

B vitamins are kind of a big deal! B vitamins are a group of vitamins that are important for maintaining overall health and well-being.

They include vitamin B1 (Thiamine), vitamin B2 (Riboflavin), vitamin B3 (Niacin), vitamin B5 (Pantothenic Acid), vitamin B6 (Pyridoxine), vitamin B7 (Biotin), vitamin B9 (folate), and vitamin B12 (Cobalamin).

This dream team is essential for various bodily functions, such as energy, brain function, metabolism, immune function, and production of healthy red blood cells.

Plus, if you've got dry skin or dark circles under your eyes, dull hair, or brittle nails, it's B vitamins to the rescue!

Who is at risk for B vitamin deficiency?

Those at risk for B vitamin deficiency, especially vitamin B12, are:

  • Vegans and vegetarians (because B vitamins are found in animal products)
  • Older adults
  • People with gastrointestinal or autoimmune diseases like Celiac, Crohn’s disease or Pernicious anemia
  • Pregnant women
  • Babies and young children of vegan/vegetarian mothers
  • People with the MTHFR gene mutation (estimated about half the population)

Signs of vitamin B deficiency

Common signs of vitamin B deficiency are:

  • Chronic fatigue/low energy
  • Frequently getting sick
  • Dull hair and skin
  • Vision problems
  • Always feeling cold
  • Mental confusion or forgetfulness
  • Tingling hands and feet

How long does it take for a vitamin B complex to work?

 It's different from person to person, and there are several factors to consider.

These are some factors that impact how long it takes to feel the benefits of taking B vitamins:

Your baseline vitamin levels: If you have very low levels of B12, it can take longer for a B12 deficiency to correct

Your diet: Eating a nutrient dense diet will help your body to absorb more nutrients more quickly. Also, things like caffeine and alcohol have been shown to hinder the absorption of vitamins

Your lifestyle: Things like smoking, vaping, and irregular sleep patterns can all impact the absorption of nutrients, because they affect the gut and liver

Medications: Certain medications like hormonal contraceptives or statins can lead to nutrient deficiencies and impact absorption

What form the vitamins come in: Vitamins come in many different forms, such as topical, capsules, gummies, powders, methylated, etc, and some are better absorbed than others. 

Gut or autoimmune diseases: Issues with the gut can impact your body’s ability to absorb and utilize vitamins

MTHFR gene mutation: People with the MTHFR gene mutation have a reduced ability to convert folic acid (B9) into its active form. More on this in a bit!

What are methylated B vitamins?

Methylated B vitamins are more effective because they're a form of B vitamins that have been converted into their active, bioavailable form. That means your body doesn't have to work as hard to absorb and utilize the vitamins, therefore you'll feel the benefits more quickly!

The MTHFR gene mutation and B vitamin absorption

Nearly half of the population has a specific gene variation, called MTHFR, that makes it more difficult to convert folic acid (B9) into the methylated form. This can lead to a range of health problems, including anemia, fatigue, mood disorders, and nerve damage.

For these people, having a methylated B vitamin is crucial to the efficacy of the vitamin on their bodies. This is especially true because MTHFR gene mutations are often associated with an increased risk of anxiety and depression

By ensuring that those with the MTHFR gene mutation get methylated B vitamins, they reduce the risk of mental health issues.

That’s why we made sure our Mood B Complete vitamins were in methylated form!



How do you know if the B vitamins are working?

One of the most common reasons people take B12 is to boost their energy levels and to improve their mental health and cognition. While it’s true that B12 gives you energy, it likely won’t happen instantly. Your body needs a steady dose of B12 every day to build up in your system.

Let’s look at how you can expect to feel over time consistently taking methylated B vitamins:

Day 1:

If you're starting off with very low levels of B vitamins, you may feel the positive effects of B vitamins on day 1! You'll likely feel more energy today, and you may feel warmer if you usually have cold hands and feet due to anemia.

30 Days:

After taking methylated B vitamins for 30 days, you may start to notice consistent energy levels throughout the day (no more afternoon crash!) and improved mood and mental clarity.

This is because B vitamins play a crucial role in energy production and neurotransmitter synthesis, which can affect your mood and cognitive function.

60 Days:

After taking methylated B vitamins for 60 days, you may experience more significant improvements in your energy levels, mood, and cognitive function. You wake up with energy to take on the day, and your problem solving skills are on point.

You may also notice shinier hair, stronger nails, and brighter skin, as B vitamins are essential for healthy hair and nail growth.

90 Days:

After taking methylated B vitamins for 90 days, you may notice significant improvements in your overall health and well-being.

You no longer need caffeine to get through the day, you're sleeping more deeply, and your mood is balanced...nothing phases you!

Additionally, if you had a deficiency in B vitamins, you may have completely resolved your symptoms related to that deficiency.

1 Year:

 If you've made it all the way to one year of consistently taking methylated B vitamins, congratulations! You're now getting the long-term benefits, such as a strong and healthy immune system, and protection of brain function. 

Since B vitamins are crucial for the production of neurotransmitters like serotonin and dopamine, you may see a reduction symptoms of anxiety, and feeling overall in a better mood.

You're no longer way colder than everyone else, it's easier to build muscle if your strength training, your digestion issues have diminished, and your energy levels remain steady.

It's important to note that everyone's body is different, and the results of taking methylated B vitamins may vary from person to person. 

How to speed up the effectiveness of your B vitamin supplements

In a hurry to improve your health? We wish we could say there's a quick fix, but there are some things you can do to speed up the process of getting your B vitamins to work:

  • Make sure your B complex vitamins are methylated for better absorption
  • Reduce alcohol and caffeine consumption
  • Get at least 20-30min of exercise a day
  • Quit smoking or vaping
  • Check if any medications you're taking cause nutrient deficiencies and talk to your doctor what you can do to correct nutrient deficiencies
  • Chew your food thoroughly and eat slowly to maximize nutrient absorption
  • Improve gut health

Ready to start your journey with B vitamins? PYM’s Mood B Complete was formulated by neuroscientists and psychiatrists as methylated B vitamins with cofactors Zinc and Vitamin D to boost absorption so you can start feeling better, faster.



  • "B vitamins and the brain: Mechanisms, dose and efficacy--a review" by David O. Kennedy, published in Nutrients in 2016.
  • "Folic Acid, Neural Tube Defects, and the Prevention of Spina Bifida" by Anne Marie C. Lawrence et al., published in Pediatrics in 2017.
  • "Vitamin B12: one carbon metabolism, fetal growth and programming for chronic disease" by Sarah M. Kimmons et al., published in European Journal of Clinical Nutrition in 2013.
  • "Vitamin B12 deficiency: recognition and management" by Joseph C. Masdeu and Raquel E. Gur, published in American Journal of Psychiatry in 2016.