Should You Inject Your Supplements?

Written by: Pippa Thackeray

February 4, 2025

Injectable supplements skip digestion, delivering nutrients like B12 and peptides straight into your bloodstream. “Faster”, “effective”, and increasingly popular, are injections the future of targeted nutrition?

Spend any amount of time on social media and you’ve more than likely heard of GLP-1. But what about injecting supplements? It’s gaining a lot of traction as a conversation topic, with many advocates promising better delivery and improved results.

The idea came about as a result of research showing that the digestive system can limit how well our bodies absorb certain nutrients. It left people thinking that if the effectiveness of oral supplements are often diminished, could it be leaving you with less than you are paying for?

Should we inject all our supplements?

The short answer is, probably not. While the concept is appealing and might seem like a tantalising solution, not every supplement benefits from injection. Oral supplements still work for most people and are generally more affordable and more convenient. There is also the issue of the health risks that come from injectable products from low quality manufacturers.

That said, injectable supplements do have a place as certain nutrients and compounds are much more effective when administered directly via injection.

The science behind absorption and bioavailability

Bioavailability refers to how much of a substance reaches circulation effectively. To understand why some people are now looking to injectable supplements to provide a solution, it helps to first look at how the body absorbs nutrients from oral supplements, and the problems that could arise from oral forms.

When you take a pill or capsule orally, it has to pass through the digestive system before reaching the bloodstream. It may sound simple, but this journey is far from straightforward.

Firstly, enzymes in the stomach and intestines break down the supplement, and depending on the nutrient, a significant portion may be lost in the process. To use an example here, many vitamins and peptides are sensitive to stomach acid and the digestive enzymes produced in the small intestine, which can degrade them before they have a proper chance to be absorbed.

Secondly, absorption depends on the efficiency of transport across the gut lining. Some nutrients, such as vitamin B12, require specific transport proteins to be present, in order to be absorbed thoroughly into the blood. So if these are lacking (as is often the case in people with conditions like pernicious anaemia or gastrointestinal disorders) absorption can be severely limited.

Explaining first-pass metabolism

Even if a nutrient does make it into the bloodstream successfully from the gut, it still has to pass through the liver before circulating around the body. This is known as first-pass metabolism. The liver processes many substances before they can exert their effects, and in some cases, this can significantly reduce the amount of active nutrient that ultimately reaches your cells.

Substances introduced directly into the bloodstream, such as through intravenous injection, bypass the first-pass effect, allowing them to reach systemic circulation without initial liver metabolism.

What is the evidence for certain nutrients to work best as injections?

Here are some of the injectable supplements you will likely hear about the most often:

Peptides
These are often used for weight management, anti-ageing, and recovery. Two popular examples are NAD+ for cellular repair and energy production and BPC 157 , known for supporting healing and reducing inflammation. You can read our dedicated articles on NAD+ and shop injectable NAD+ at Healf.
Vitamin B12
Famous for its role in boosting energy and supporting cognitive function, B12 injections are ideal, and sometimes a necessity for those who struggle with absorption issues. This is a common choice for people on vegan diets or with conditions like pernicious anaemia.
Glutathione
Hailed the “master antioxidant,” this powerhouse supports detoxification and glowing skin. It is made naturally in the liver, but supplemental doses make it an ideal choice for those who want to focus on cellular repair and boosting immune function as well as warding off diseases such as heart disease, neurological disorders and liver disease, to name a few.
Amino Acids
Amino acids are required for muscle recovery and for achieving optimal physical performance. Numerous studies have shown that branched-chain amino acid (BCAA) supplementation can reduce muscle soreness and damage after exercise. Moreover, there is evidence to support better absorption from intravenous administration, from studies completed in older subjects.
Iron
For people with severe anaemia, injectable iron offers a faster and more effective medical solution than oral alternatives, which can often cause side effects like digestive upset.

Is this delivery method for everyone?

The answer is perhaps more nuanced than it may appear. With injectable supplements, they come with clear benefits if you look at the scientific research and evidence to back them up, as we have just discussed. But there are some other factors to consider:

Convenience : Whilst there are some great at home injectable products on the market to consider, many others will require professional administration, which means appointments with a healthcare provider are a must in order to maximise safety, reducing risk of overdose and infection.
Health status : If you don’t have a condition that limits absorption or a deficiency requiring immediate correction, oral supplements may still be a great and adequately effective option.

You should always consult a qualified professional before starting any new injectable regime.

The takeaway on injectables

Injectable supplements span a wide variety of nutrients and purposes for their use. Therefore, a simple yes or no answer to their use is hard to give.

The true answer would sound more like, “it’s personal”, due to the intricacies and subtleties that make us all different from one another. Issues such as our genetics, and our medical histories make our cases unique.

That said, there are many injectable supplement forms that already come recommended by medical professionals for treating very common deficiencies such as iron or B12. Similarly, injectable supplements like NAD+ have already taken off in the wellbeing space due to the health optimisation benefits they possess.

More work is currently underway to understand the true potential of the vast variety of injectable supplements and to ensure their safety if rolled out for public use.

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This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Healf

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