Your immune system is your body’s powerhouse. It’s your body’s best defender and first responder. 

But sometimes, your immune system needs a little help. 

The good news is that your body already has the tools it needs to perform well, as in the case of IGF-1. But if your body could use something extra, IGF-1 supplements might do the trick. 

Here’s what IGF-1 is, how it works on your immune system, and ways that you can increase IGF-1 naturally. 

What is IGF-1?

First, you need to know what IGF-1 actually is. 

Insulin-like growth factor 1, or IGF-1, is a growth hormone. It was discovered in 1957 along with IGF-2 and designated as a “sulphination factor” for its ability to stimulate sulphate incorporation in rat cartilage. 

It received the name IGF-1 in 1976, when two scientists isolated it from a human serum. It’s called “insulin-like” because of its structural resemblance to proinsulin, a biosynthetic precursor to insulin. 

Chemical Structure and Receptors

To be clear: IGF-1 and other members of the IGF family are not insulin. 

Instead, they are a family of insulin-related peptides. This is a category of small, structurally related proteins and signaling molecules including insulin, insulin-like growth factors, and relaxin. 

IGF-1 in particular is a small protein consisting of 70 amino acids. It has an A and B chain connected by disulphide bonds and a C chain with 12 amino acids. Structurally, then, IGF-1 is remarkably similar to insulin, which is why it’s able to bind with insulin receptors. 

Humans have a naturally-occurring IGF-1 receptor, structurally similar to normal insulin receptors. The liver has the highest concentration of IGF-1 ligands, but the receptor’s mRNA is almost undetectable due to downregulation. 

However, IGF-1 and its receptors aren’t located solely in the liver. In fact, there are several tissues that secrete it, and the secretion site seems to determine how the hormone is used. 

The most common secretion site is the liver, where it’s used as an endocrine hormone, but it’s also been seen in cartilaginous cells and is assumed to act as an oncogene, which acts as a gas pedal for determining how fast cells grow.  

The Role of IGF-1

As we noted earlier, the secretion site of IGF-1 seems to play a key role in how the hormone is utilized in the body. 

So, if you want to say what it does, it really depends on where it’s coming from. 

Since the liver is the most common secretion site, it’s most often seen performing a role that aids in liver function. Specifically, it acts as an endocrine hormone. Hormones of this type help the body regulate metabolism, energy production, growth, and the body’s response to injury. 

Insulin is also an endocrine hormone, working to lower the blood sugar and stimulate the metabolism. 

But while IGF-1 is similar to insulin, it isn’t typically discussed in terms of blood sugar. It’s actually discussed as a growth hormone. Most of the time, when used in other tissues, it serves some kind of growth-related purpose, though the action and expression of each protein is cell- and tissue-specific. 

The Nervous System

Take the nervous system, for example. 

Because the IGF family resembles insulin, it’s able to cross the blood-brain barrier and serve as an endocrine hormone. 

In plain English? Where there’s IGF-1, there’s growth. 

Studies of rats and mice have found a proliferation of IGF-1 in the brain. At every stage of development, higher expression of IGF-1 is associated with increased neural precursors. Mice with overexpression of IGF-1 showed increased postnatal brain growth, while those with deficiencies had impaired neuronal dendritic and somatic growth (though they didn’t have impaired brain function). 

If you have no idea what that means, it’s simple. More IGF-1=more brain growth after birth. Less IGF-1=slower brain growth. 


Since growth and metabolism are intricately entwined, our metabolic rate plays a key role in our aging and longevity

Basically, insulin and the IGF family play a role in regulating how fast or slow our metabolism works. This isn’t just about how fast we digest our food. It’s about how quickly we utilize energy. 

If our body is burning through energy faster, it’s often associated with growth. After all, the body needs supplies in order to grow. 

If our metabolism slows down, we aren’t able to grow because we aren’t using energy as quickly. This is why young adults (with relatively high metabolisms) continue to grow and change, while older adults (whose metabolisms have slowed) deteriorate. 


Growth and metabolism are critical to how our bodies work. But when they’re out of control, you get a familiar disease: cancer. 

We mentioned earlier that IGF-1 acts as an oncogene. If you’re familiar with word roots, you’ll recognize the similarity to the word oncology, i.e. the branch of medicine that deals with cancer. 

Cancer takes many forms, but the basic elements are always the same: unregulated cell growth. 

When oncogenes work properly, they’re a cellular speedometer. They control how fast or slow a cell grows, signaling a cell’s metabolic rate to increase or decrease. They become a problem when they mutate or there’s too many of them, cells begin to grow uncontrollably, without regard for the system they’re supposed to support. 

IGF-1 and the Immune System

But IGF-1 also plays a critical role in another part of the body: the immune system. 

Your immune system is responsible for fighting off a host of environmental agents, from microbes to chemicals to foreign tissues. And while we often talk about the role of growth factors in, well, growth and development, the link between these hormones and immune function is a recent discovery. 

It might seem like comparing and apple and a baseball until you think about what the immune system does. 

The immune system is responsible for fighting off invaders, but it’s also critical in wound healing and fighting off infection. 

In order for the body to heal, it has to be able to grow healthy tissue. And the balance of growth and inflammation is key to both fighting off infection and regenerating healthy cells. 

This is where IGF-1 and the immune system work together. 

Immune Integration

One of the big things that IGF-1 does is to aid in immune integration. 

Think of it this way. 

Immune reactions and inflammation are known to affect cell growth. It makes sense–you don’t want to start growing healthy cells if the wound site is still at risk of infection. Otherwise, the new tissue will get infected and make the whole situation worse. 

On the flipside, your body has to be able to switch off inflammation in order to grow. 

IGF-1 has been shown to decrease as a result of aging and chronic disease. In fact, it’s been identified as one of several factors responsible for the degeneration of aging skeletal muscle–as we age, our IGF signaling decreases, creating a loss of muscle as there is no signaling to grow new muscle in its place. 

But inflammation due to chronic disease has also been shown to decrease growth. 

Immune Coordination

So, if IGF hormones and the immune system work together, it only makes sense that IGF-1 signaling would have some effect on inflammation. 

IGF-1 in particular has been shown to modify the effects of inflammation by influencing molecular mediators behind inflammation. However, these mediators can in turn affect the behavior of IGF-1 and other hormones, resulting in a complex relationship. 

It plays out in a wide variety of ways depending on the situation. What it boils down to is this: IGF can block inflammatory mechanisms to prevent cellular shutdown, and inflammatory mechanisms can in turn block IGF as needed. It’s all about internal regulation. 

Stimulation of Regulatory T-Cells

Another way that IGF can help regulate the immune system is through the production of regulatory T-cells. 

T-cells are a type of white blood cell that plays a critical role in immune function. There are several different types of T-cells, but regulatory T-cells in particular are responsible for suppressing the immune system so that it doesn’t overreact to outside stimuli, as in the case of autoimmune disorders. 

Studies of IGF-1 signaling have shown that it plays a role in the stimulation of regulatory T-cells, but not in the production of other T-cells. In particular, it affects surface cell markers of regulatory T-cells associated with cell activation and proliferation. 

In plain English, IGF-1 targets regulatory T-cells specifically and tells them to get to work in quieting the immune system down. 

Inhibiting Inflammation of the Intestine

It makes a lot of sense, then, that we can see this inhibitory action in other areas of the body, like the intestine

Research on IGF-1 and intestinal cells found that intestinal epithelial cells actually produce IGF-1. These cells form a critical part of the intestinal epithelial barrier, signaling between the outside environment and the internal environment. They also produce a number of molecules, including IGF-1, to regulate the intestinal environment. 

The study found that IGF-1-primed monocytes (a type of white blood cell) markedly improved the severity of intestinal inflammation, furthering the theory that IGF-1 can help counteract the inflammatory effect of the immune system in various parts of the body. 

Managing IGF-1

So, what does all of this have to do with you? Think of it this way. 

Our bodies put a lot of work into maintaining a balance between necessary inflammation and problematic inflammation. You need inflammation to kill off foreign microbes, but too much inflammation will actively harm your cells. 

Glucose and hyperglycemia are known to be pro-inflammatory, which means that out-of-control glucose levels play an active role in promoting harmful inflammation. 

IGF-1, on the other hand, is actively anti-inflammatory. It’s part of how your body safely regulates insulin levels and inflammation, protecting your tissues from harm. 

Without enough insulin, your body won’t be able to regulate your blood sugar (the mechanism behind diabetes). But with too much insulin, your blood sugar levels remain too low and your body doesn’t have enough energy to function. 

Inflammation is a necessary part of the immune system, but if it spins out of control, your cells become damaged and you can’t heal properly. 

IGF-1 helps keep both of these things under control. So, if you want to live a healthier life, keeping tabs on your IGF-1 levels may be a good place to start. 

Foods That Boost IGF-1

One way to do this is through foods that help boost IGF-1 levels in your body. 

To be clear, almost all IGF-1 is produced in the body. Eating certain foods won’t make you digest IGF-1. However, certain foods may work to indirectly boost IGF-1 production. 


Dairy is one major example of this. 

Research has shown that cow milk and other dairy products are positively associated with the production of IGF-1 in children. Milk contains IGF-1, but IGF-1 levels were also shown to be higher among those who consume milk and dairy products more frequently. 

However, if you do try to boost your IGF-1 intake through dairy, you want to make sure it’s not too high. If you’re worried about this, look for dairy products marked “rBGH free” or “rBST free”. Foods certified organic are often a safe bet. 


Magnesium is a common mineral found in green leafy vegetables, nuts, and legumes. It’s been cited in everything from promoting bone density to boosting calcium absorption to relieving anxiety. 

Now, researchers are saying that magnesium could play a critical role in IGF-1 bioactivity

IGF-1 is important in the aging process because it’s a growth hormone. Observational studies of elderly people saw a strong positive association between low IGF-1 levels and muscle weakness. 

Data also suggests that poor mineral consumption, which is frequently seen in older populations, can exacerbate the decline of IGF-1 brought on by age. 

Magnesium, in particular, is involved in multiple metabolic pathways. And like IGF-1, magnesium can independently benefit muscle function in the elderly. What’s interesting is that IGF-1 seems to support cellular metabolizing of magnesium, which in turn acts as a determinant for insulin processes. 

While our magnesium requirements don’t change with age, our consumption of it often declines with age, even as the importance of magnesium in maintaining healthy functions shoots up. 

The long and the short of it is this: magnesium and IGF-1 work together to help bolster your muscle performance. If you need more magnesium (and more IGF) try these foods first: 

  • Dark chocolate
  • Avocados
  • Legumes (black beans, lentils, chickpeas, peas, etc.)
  • Nuts (cashews, almonds, Brazil nuts)
  • Seeds (pumpkin, flax, chia)
  • Whole grains (buckwheat, quinoa)
  • Fatty fish (salmon, halibut, mackerel)
  • Leafy greens (kale, spinach, collard greens, mustard greens, etc.)

Luckily for you, all of these foods are easy to locate and have plenty of other health benefits going for them too. 


Zinc is a major player in the human body. More than 200 enzymes that play a role in major metabolic processes require zinc to do their job properly. 

Zinc deficiency is also associated with a number of problems that should sound familiar, if you’re paying attention to what IGF-1 does: poor wound healing, inflammation, dermatitis, and weakened immune response. 

Interestingly, zinc also seems to be involved in the nutritional regulation of IGF-1. 

In animal models, for example, severe zinc deficiency was linked to decreased hepatic IGF-1 gene expression, suggesting that zinc plays a crucial role in regulating insulin and IGF-1 levels in the body. It should come as no surprise, then, that low zinc levels are associated with poor IGF-1 circulation, even in the presence of other factors that should mitigate this effect. 

The connection between IGF-1 and zinc can be at least partially explained by zinc’s powerful antioxidant properties. If you’ll recall, antioxidants help prevent oxidative damage to cells, reducing the effects of ongoing cell damage which is linked to serious negative health effects, like the development of cancer. 

The easiest way to get zinc through your diet is through meat, particularly red meat such as beef and lamb. Keep in mind, though, that high amounts of red meat have long been shown to be bad for you. 

So balance your red meat intake with other zinc sources, such as shellfish, legums (lentils, chickpeas, beans), seeds (hemp, pumpkin, sesame), nuts (pine nuts, cashews, almonds) and dairy. Milk, in particular, has a high amount of bioavailable zinc (it’s easy for your body to absorb it). 


Selenium, like zinc and magnesium, is critical to several of the body’s metabolic pathways. 

It’s a mineral that plays a key role in maintaining your skeletal and muscular health. It does this through the maintenance of selenoproteins, particularly selenoprotein N, which regulates calcium mobilization for early muscle development. 

It should come as no surprise, then, that recent research has suggested that selenium plays a role in IGF-1 bioactivity, with a strong correlation between selenium and IGF-1 that didn’t budge regardless of age, sex, body mass index, alcohol intake, smoking, or major chronic diseases. 

So, if you want a boost of IGF-1, one place to start is selenium. These foods all pack a major punch on that front: 

  • Turkey
  • Ham
  • Brazil nuts
  • Fish (yellowfin tuna, sardines, oysters, clams, halibut)
  • Pork
  • Beef
  • Chicken
  • Cottage cheese
  • Eggs
  • Brown rice

Basically, if you’re a carnivore, you’ll have a much easier time keeping your selenium levels (and IGF-1 levels) in check. 

Vegetarians and vegans should keep in mind that there are non-meat sources of selenium, from mushrooms to sunflower seeds to baked beans and oatmeal. The trick is to vary your intake so that you don’t wind up with an overabundance of specific nutrients. 

Foods That Reduce IGF-1

Keep in mind, however, that there are certain foods which actively reduce IGF-1 levels. Here are a few to watch out for. 

Green Tea

Green tea is often cited as a wonder-drink for health nuts. Unfortunately, in this case, green tea doesn’t come out on top. 

This is because of the polyphenols in green tea, which do have major benefits to your body in other areas. These same polyphenols are associated with a marked reduction in IGF-1 and the factors needed to encourage it. 

On one hand, this is good news if you’re trying to inhibit growth, as in the case of cancer. On the other hand, you don’t get the regenerative benefits attached to IGF-1. 


Alcohol might make for a fun night on the town, but it isn’t good for your health. This is just one of the many reasons why. 

To be clear: moderate alcohol intake won’t be enough to hurt you. Research has found that moderate alcohol intake is associated with an acute, profound decrease in IGFBP-1 and a less significant decline in IGF-1. 

The issue is when you drink to excess. In that case, the decline in IGF-1 is much more marked and can create serious problems. This is likely due to the effect of alcohol on the liver, since the liver is the primary producer of the hormone. 

If you needed a reason to stop drinking (or drink less) this is it. 


If you know you have dietary restrictions, getting your IGF-1 levels through food could sound like an impossible task. Even if you don’t have dietary restrictions and you’re bad at staying on top of your diet, things can get hairy. 

This is where an IGF supplement can come in handy. 

Nothing can replace a healthy diet, but if you need a targeted boost to give you an edge, supplements can help make up the difference. It’s also a way for you to get your IGF levels where they need to be without consuming foods that you’re allergic to or dislike. 

Finding an IGF-1 Supplement

IGF-1 works hard to keep your body in prime condition. So why not help your body do a good job? After all, when your body works for you, you’re able to live life to the fullest. 

We know that quality is a top concern. That’s why we strive to provide the best possible products. 

Stop fighting with your body. Make it work for you instead–with science. 


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