I ran IGTROPIN once at the same dose of media grade and got the same results,and saved an arm and a leg.Would like to hear other views,as Ive had a few Enquiries on this.
IGF-1: Media or Receptor Grade?
Can it be both financially and physically beneficial to pay almost twice the price for receptor grade IGF compared to media grade IGF? It can be and it is! On the financial side, while it is up to twice as expensive, better results require less than half as much. For example, if for the same gains I can use 80 mcg of media grade for $.12 per mcg or 20 mcg of receptor grade for $.30 per microgram, the result is $9.60 for each injection of media grade or $6.00 for each injection of receptor grade. That is a huge savings for using a quarter of the product to inject while getting the same results.
However cost is not the only benefit. There has been a lot of speculation on underground boards lately about the merits of receptor grade vs. media grade hLONG R3IGF-1 (herein referred to as L-IGF), with very little science to back up any claims or bantering. This article will focus on the science side of studies and results using both in-lab studies, as well as real world information from top level athletes.
L-IGF is an 83 amino acid analog of human IGF-I comprising the complete human IGF-I sequence with the substitution of an Arginine for the Glutamine at position 3 (hence R³), and a 13 amino acid extension peptide at the N-terminus.
L-IGF binds specifically to type 1 IGF receptors and promotes cell proliferation, as well as increases cell survival. It has been shown to be equivalent to insulin in supporting cell growth and depending on the situation may outperform insulin in viability and protein production. It is engineered to have a higher biological potency than native IGF-I or IGF-II and has several advantages over recombinant insulin, potency being among them. Published research has shown that supplementation of cell cultures with IGF at a much lower concentration results in equivalent or better productivity than supplementation with standard concentrations of insulin. L-IGF is better able to stimulate the Type I IGF receptor and thus induce a higher level of activation of intracellular signaling molecules which are responsible for promoting cell survival by inhibition of apoptosis.
So as a basic premise you can clearly see the advantages between IGF-1 and the LONG™ version of IGF. The chart below (Figure 1) clearly shows the difference in protein synthesis in cell cultures utilizing equivalent grades (receptor) of IGF-1. The use and uptake of the amino structure is significantly different between the two peptides. Unless you have been stuck in the jungle for the last 2 years, you already know that. What we are working on is trying to determine if there really is a difference between receptor grade and media grade L-IGF.
Figure 1
Look at Figure 2. You can clearly see in both studies a fairly significant difference between IGF and L-IGF. But if you look more closely and compare the two charts (F 1,2) you will see a very surprising difference – the % stimulation of protein synthesis in (Figure 1) receptor grade L-IGF is over 400%, while the (Figure 2) media grade is less than 120%. That is an astounding difference. So what does that mean?
Figure 2
Remember your 9th grade biology class? If not here is a real basic understanding of protein synthesis. It is the process whereby DNA encodes for the production of amino acids and proteins. It involves transcription, the synthesis of a protein, where the corresponding RNA molecule is produced by RNA transcription. One strand of the DNA double helix is used as a template by the RNA polymerase to synthesize a messenger RNA (mRNA). This mRNA migrates from the nucleus to the cytoplasm. During this step, mRNA goes through different types of maturation including one called splicing when the non-coding sequences are eliminated. The coding mRNA sequence can be described as a unit of three nucleotides called a codon.
Translation is the RNA directed synthesis of polypeptides. This process requires all three classes of RNA. Although the chemistry of peptide bond formation is relatively simple, the processes leading to the ability to form a peptide bond are exceedingly complex. The template for correct addition of individual amino acids is the mRNA, yet both tRNAs and rRNAs are involved in the process. The tRNAs carry activated amino acids into the ribosome which is composed of rRNA and ribosomal proteins. The ribosome is associated with the mRNA ensuring correct access of activated tRNAs and containing the necessary enzymatic activities to catalyze peptide bond formation.
The chart below is standard in most high school biology text books and may help provide a clearer understanding of the process. While it is quite complex, it is very important to understand that the difference between 400% and 120% is incredibly significant in scientific studies.
Figure 3
But we are not done yet. There are more tests that show a significant difference between receptor grade and media grade. If you look at Figure 4 below for comparison with IGF in Figure 5, we can establish a link between L-IGF having superior binding to cells by RIA. Both tests were performed by radioreceptor assay, which is a variant test of radioimmunoassay, a procedure that follows the basic principle of radioimmunoassay where there is competition between a radioactive and a non-radioactive antigen for a fixed number of specific antibody binding sites.
Figure 4
Figure 5
Receptors for peptide, protein and glycoprotein hormones, and the catecholamines are located on the plasma membranes of their target cells. Preparations of the receptors may be used as specific, high-affinity binding agents for these hormones in assay methodology akin to that for radioimmunoassay. A particular advantage of the radioreceptor assay is that it has a specificity directed towards the biologically active region of the hormone, rather than to some immunologically active region that may have little (or no) involvement in the expression of hormonal activity. In general, there is good correlation between radioreceptor assays and in-vitro bioassays; differences between results from radioreceptor assays and radioimmunoassays are similar to those noted between in-vitro bioassays and radioimmunoassays. The sensitivity of the method is such that normal plasma concentrations of various hormones have been assayed by this technique.
Purity is an oft discussed issue in the grades of L-IGF. Numbers are being thrown around the net about the “purity” of distributors L-IGF, with numbers ranging from 85% to 99%. Obviously the lower the number, the less purity and less bioavailability you will have from your L-IGF. What is needed is to establish some baseline numbers so we have a working model to gauge the efficacy and usefulness of your L-IGF. The only legitimate, legal manufacturer of all forms of IGF, GroPep, lists their media grade L-IGF as >85% and their receptor grade as >95%.
Hold on a minute, I thought XYZ said their media grade is 97%, how can that be? Well, it can’t. The fact is that GroPep is the only licensed manufacturer of IGF and all variant forms (IGF-1, IGF-II, IGFBP, etc), so if your company is trying to tell you that their L-IGF is more pure than the basic standard of receptor at >95%, than you are being sold snake oil. The other concern people have is that most receptor grade is listed at 99% pure, which it most certainly can. If you notice the “greater than” sign, it means that all receptor grade IGF must be more than 95% pure for it to be classified as receptor and each batch is assigned an assay report where the IGF is measured by HPLC and N-terminal sequence analysis for accuracy. They also measure the molecular weight in Daltons by mass spectrometry.
Back to our purity problem, obviously if the manufacturer states that receptor is minimum >95% pure, then we certainly can’t have media grade that is close to that number. Media grade is >85% and can be up to <95% pure, so any other claims or numbers are misleading. Make sure you question any source you choose to purchase from if they are claiming otherwise. Ask to see reports on where they source from and what the assay report shows to verify their claims. Make them back up what they are asking you to spend your hard earned money on.
In conclusion, while both forms of L-IGF will work, and both will perform the same intended task, there is a major difference between the two forms. The difference in purity is a significant number, especially to a scientist. If you were to perform cell culture tests in a lab, the amount of protein synthesis and uptake, which is to include cell proliferation, you would want to use the highest purity available. A difference of more than 1% is not acceptable and can cause results to vary significantly.
Most people have never tried receptor grade L-IGF because it is extremely expensive to purchase in small quantities, and not very many companies have the capital to purchase the amount needed to make it reasonable to retail. I have personally contacted GroPep from my research firm to inquire about bulk purchases of L-IGF receptor grade and I can assure you that if you have enough money to buy in very large quantities, you certainly can market it at very affordable prices to consumers and still have a profit margin to make it worthwhile.
So while most companies selling media grade will claim that no company can sell receptor and it is just re-labeled media, that is certainly not always the case. Of course there are always unscrupulous business men in this industry which is why I recommended you ask for information before you spend your money.
The real question to be answered is, “Is it worth spending the extra money on receptor grade when people get results on media grade?” The answer is a resounding yes! With the bioavailability being a difference of up to +/- 10%, when <1% makes a significant difference in cell culture lab results, then spending the money is not the question, because the money will be less when purchasing receptor grade.
How’s that? Well look at it this way, using hypothetical pricing for both products, if media grade retails for $120 on average and receptor grade retails for $300 on average, both being for a 1000mcg bottle, what is needed is to know the amount of product needed for use, so the cost can be averaged per use.
Media to receptor grade comparisons in lab studies show a difference of 1% can mean the mcg amount utilized can be as much as a 1:4 ratio, being that for every 1 mcg of receptor grade used, you must use 4 mcg of media grade for equivalent results. Since most guys need to use 80-100mcg of media grade per day for noticeable results, that means if you use real receptor grade L-IGF you will only need to use 20-33mcg per day. That is a significant difference at only a 1% difference; remember there is a tolerance difference of +/- 10% by Gropep standards for cell culture standardization.
So now back to the cost issue. If you need on average 80mcg per day of media grade at $120 a bottle, that is $.12 per mcg or $9.60 per use. If you use receptor grade at $300 per bottle, that is $.30 per mcg or $6.00 per use. You save $3.60 per injection using receptor grade, a significant savings. And that is at hypothetical prices, just shop around and do the same math. I have seen media as low as $100 per bottle and receptor as low as $230 per bottle when both are bought in bulk.
It is up to you how you spend your money, but for me I want the most bang for the buck. The above information is current and valid as provided by GroPep and studies found on the NCBI website. Don’t waste anymore of your money.
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Originally Posted by plzr8
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