Science · Nua Series

How much matters.
So does what it is.

Purity, form and independent verification in omega-3. This page shows what we chose for NuaDHA® and NuaEPA®, why, and which source each sentence rests on.

I am choosing an omega-3 I am looking into vitamin D

Last updated: 10 October 2026

In the NUA range, purity, form and dose are designed together.

On an omega-3 label, look at two lines: the amount of fish oil in the capsule and the amount of EPA or DHA in that oil. Purity is a fact about composition. It shows how much of the fish oil is omega-3.

NuaDHA® and NuaEPA® reach a purity of above 90% through molecular distillation and re-esterification. More than 90% of the fish oil in the capsule is omega-3 (mostly DHA in NuaDHA®, mostly EPA in NuaEPA®). The higher the purity, the more active ingredient and the less of other fatty acids the same capsule carries.

So read the amount of DHA or EPA per capsule, not the number of capsules. The conditions of health claims depend on this amount too. The DHA claims on brain function and vision, for example, apply with a daily intake of 250 mg DHA. Two things set the purity: the species of source fish and how carefully the distillation is done.

What to check on the label and in the test report when you pick up an omega-3 box is set out in six questions in our guide How to choose an omega-3.

Omega-3 purity · share of omega-3 in the fish oil

NuaDHA® · NuaEPA®re-TG form, IFOS 5★

90%⁺

Purity is a fact about composition. The IFOS lot report does not give a purity percentage. It gives the amount of EPA and DHA per capsule in mg. The 90%+ figure is calculated from the amounts measured in IFOS testing. The label shows the minimum amount the product must still contain at the end of its shelf life. That is why a calculation based on the label figures can come out lower.

Active ingredient per capsule

NuaDHA® carries 1000 mg DHA in one capsule. NuaEPA® carries 1200 mg EPA in one capsule. The number on the label is the active ingredient itself, not the total oil.

Less filler oil

During purification almost all of the non-omega-3 fats in the fish oil are removed. A purity above 90% means that no more than one tenth of the fish oil in the capsule is made up of fatty acids other than omega-3.

Results are public

The amount per capsule, contaminants, freshness and heavy metals are measured in a programme independent of us. Every production lot is tested in the IFOS programme. Results are published on the public IFOS results page. With the lot number on your box you can find the test report for your own lot in three steps.

Not ethyl ester. Re-esterified triglyceride.

In natural fish oil, omega-3 fatty acids sit in a triglyceride (TG) structure, bound to a glycerol backbone. To concentrate the oil, this bond is broken and the fatty acids are bound to ethanol, which gives the ethyl ester (EE) form. NuaDHA® and NuaEPA® go one step further after concentration. The fatty acids are bound back onto a glycerol backbone and return to the re-esterified triglyceride (re-TG) form. This structure is close to the natural triglyceride structure the body knows from food. Re-esterification takes an extra production step and extra cost. The whole NuaDHA® and NuaEPA® range is in re-TG form. The label says the product is in triglyceride form. A concentrated fish oil in triglyceride form is re-TG, because the oil is first separated as ethyl ester and then turned back into a triglyceride structure.

EEEthyl ester: the intermediate form of the concentration stage. The fatty acid is bound to ethanol. This form does not occur in natural oils.
TGre-TG: the fatty acids are bound back onto a glycerol backbone and the form returns to the triglyceride structure of natural fish oil.

In some human studies, the re-TG form has been associated with higher omega-3 levels in the blood compared with the ethyl ester form.[3] In a six-month randomised, double-blind study in which the same amount of EPA and DHA was taken in re-TG form, the omega-3 index rose faster and further than in the ethyl ester group.[4] Results in this field can differ from study to study. Absorption also depends on taking the capsule with a meal and on the fat content of that meal.[5]

STEP 01

Concentrate

Oil from wild anchovy caught by sustainable fisheries is purified by molecular distillation at mild temperature and pressure. EPA and DHA are separated from each other and concentrated.

STEP 02

Re-esterify

The concentrated fatty acids are moved from the ethyl ester intermediate back onto a glycerol backbone: re-TG. The oil is then filled into bovine gelatine soft capsules in Spain. The gelatine comes from a halal-certified producer.

STEP 03

Verify

The IFOS programme tests contaminants (PCB, dioxin, furan), oxidation, heavy metals and label accuracy. Results are published on the public IFOS results page.

Why are EPA and DHA separate?

Not in one capsule. Separate and pure.

EPA and DHA are two different fatty acids, and the claims the regulation allows for each are different. Instead of mixing them in one capsule, we separated them. Each one comes in its own capsule, in a high amount and in pure form.

Docosahexaenoic acid

DHA

DHA is the most abundant omega-3 fatty acid in brain and retinal tissue and one of the structural components of nerve cell membranes. DHA therefore has authorised health claims, assessed by the European Food Safety Authority (EFSA) and listed in the Turkish Food Codex[1][2]. NuaDHA® 1000 provides 1000 mg DHA in one capsule, well above the condition of these claims.

Authorised health claims*
Claim	Condition
DHA contributes to the maintenance of normal brain function.*	250 mg DHA a day
DHA contributes to the maintenance of normal vision.*	250 mg DHA a day
Maternal docosahexaenoic acid (DHA) intake contributes to the normal brain development of the foetus and breastfed infants.*	250 mg + an extra 200 mg DHA
Maternal docosahexaenoic acid (DHA) intake contributes to the normal development of the eye of the foetus and breastfed infants.*	250 mg + an extra 200 mg DHA

All authorised claims and their conditions

Eicosapentaenoic acid

EPA

EPA (eicosapentaenoic acid) is the only active ingredient in NuaEPA® 1200: 1200 mg in one capsule, in re-TG form, at a purity above 90%. It comes from a sustainable anchovy source and is tested in the IFOS programme. It is the evening half of the DHA in the morning, EPA in the evening routine.

1200 mg pure EPAre-TG form90%+ purityIFOS 5★NSF Sport® (90 capsules)

A note on transparency: EPA has no authorised health claim on its own. The regulation allows general benefit statements only when they come with an authorised health claim, so we make no benefit statement at all about NuaEPA®. We describe only its content, form, purity and independent test results.

What we say has a source. What we leave out has a reason. NuaEPA® 1200 contains 1200 mg EPA in re-TG form at a purity above 90%. IFOS results for each lot are published on the public IFOS results page.

Omega-3 by your preference

Instead of a mixed formula, each fatty acid has its own capsule and you make the choice. You can see which one suits you in the short quiz EPA or DHA?

If you prefer DHAPure, high-dose DHANuaDHA® 1000 · morning, with food

If you prefer EPAPure, high-dose EPANuaEPA® 1200 · evening, with food

If you prefer bothDHA in the morning, EPA in the eveningChoose the right omega-3

NUA separates EPA and DHA and offers them as two separate pure products. NuaDHA® and NuaEPA® are made in partnership between Longevicals and NUA Biological Innovations.

The name behind the formulationsDr. Mercedes AguirreCo-founder and R&D Director · NUA Biological Innovations Our science partners

We say it. Others measure it.

A purity statement is only worth as much as whoever measured it. That is why we put our products into programmes run by organisations independent of us, and open the records to you.

IFOS 5 Stars

International Fish Oil Standards (IFOS) is a widely recognised independent testing programme for fish oil supplements. Every NUA production lot is tested in this programme and the results are published on the public IFOS results page. The lot report has four test groups: amount and label accuracy, contaminants (PCB, dioxin, furan), freshness (oxidation) and heavy metals. The report shows no stars. Passing all four test groups corresponds to the IFOS 5-star rating. Five stars is the highest rating.

Results are public4 test groups

NSF Certified for Sport®

An independent certification programme developed for athletes. The product is screened for more than 280 banned substances. It is verified that the label matches the contents exactly and that the production site is audited. The 90-capsule packs of NuaDHA® 1000 and NuaEPA® 1200 carry this certification.

280+ banned substances90 capsules

Example lot analysis

Every production lot is measured in an independent laboratory in the IFOS programme. A concrete example from one lot report:

LaboratorySGS Nutrasource (IFOS)

ProductNuaDHA® 1000

LotLot 3309-1-25

Label DHA1,000 mg

Measured DHA1,185 mg

Oxidation (TOTOX)8.78 · limit 19.5

ProductNuaEPA® 1200

LotLot 3304NS-1.2-26

Label EPA1,200 mg

Measured EPA1,224 mg

Oxidation (TOTOX)6.69 · limit 19.5

In the seven NuaEPA® 1200 lot reports we reviewed, measured EPA is between 1,224 and 1,262 mg per capsule and the oxidation value (TOTOX) is between 6.69 and 12.36. The IFOS limit is 19.5. TOTOX shows how oxidised the oil is, in other words how fresh it is. The lower the value, the fresher the oil.

The label shows the minimum amount the product must still contain at the end of its shelf life. The actual amount is usually above this and can be seen in the IFOS lot reports. This difference does not change the recommended daily intake.

A shoal of small, silver anchovies swimming together in open water — Illustrative image

Sustainable source

The source of NuaDHA® and NuaEPA® is anchovy, a small, short-lived fish low in the food chain. A short lifespan is linked to low build-up of heavy metals in its tissues. Sustainable fishing keeps the source available for the future.

AnchovyLow build-up

A certificate is not a marketing promise.

A certificate logo is not a promise printed on the box. It is a result that an organisation independent of us has measured in its own laboratory and signed off for that lot. That is why IFOS, NSF and third-party analyses are not decoration for us. They are measurements made independently of us. Every production lot is tested in the IFOS programme. Results are published on the public IFOS results page. The NSF Certified for Sport® listing covers the 90-capsule NuaDHA® and NuaEPA® packs. In both records the products are listed under the manufacturer's name, NUA. We do not ask you to believe without seeing the evidence. Look, ask questions, then decide.

See the IFOS results View the NSF listing

Purity, form and an independent record, all in one place.

Explore the Nua Series

Short glossary.

One-line explanations of the technical terms used on this site.

EPA and DHA: Two long-chain omega-3 fatty acids found in fish oil: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The Nua Series offers them in separate capsules.
Purity (90%+): A fact about composition that shows how much of the fish oil in the capsule is omega-3. 90%+ purity means more than 90% of the fish oil is omega-3.
re-TG form: Re-esterified triglyceride. After purification, the fatty acids are bound back onto a glycerol backbone, as in natural fish oil. All Nua products are in this form.
Ethyl ester (EE): The intermediate form created while fish oil is concentrated. The fatty acid is bound to ethanol. The re-TG process turns this form back into a triglyceride structure.
IFOS: An independent programme that tests fish oils lot by lot for purity, oxidation and contaminants. Results are published openly.
Heavy metals and mercury: IFOS testing measures heavy metals such as mercury, lead, cadmium and arsenic, and contaminants such as PCB and dioxin.
TOTOX: A total value showing how far the oil has oxidised (gone stale). The lower it is, the fresher the oil. The IFOS limit is 19.5.
Lot number: The production lot code on the box. With this number you can find the test report for your own lot on the IFOS results page in three steps.
NSF Certified for Sport®: An independent certification programme that screens the product for more than 280 banned substances. The 90-capsule NuaDHA® 1000 and NuaEPA® 1200 packs carry this certification.
Longevity: An approach that cares about the quality of the years as well as their number. A pro-longevity approach looks after quality of life as much as the number of years.

Common questions.

Purity is a fact about composition. It shows how much of the fish oil in a capsule is omega-3. In NuaDHA® and NuaEPA® this share is above 90%. So more than 90% of the fish oil in the capsule is omega-3 (mostly DHA in NuaDHA®, mostly EPA in NuaEPA®), and no more than 10% is other fatty acids. The IFOS lot report does not give a purity percentage. It gives the amount of EPA and DHA per capsule in mg. The 90%+ figure is calculated from the amounts measured in IFOS testing. The label shows the minimum amount the product must still contain at the end of its shelf life. That is why a calculation based on the label figures can come out lower.

Ethyl ester (EE) is the intermediate form created while fish oil is being concentrated, with each fatty acid bound to ethanol. In the re-esterified triglyceride (re-TG) form, the fatty acids are bound back onto a glycerol backbone, as in natural fish oil. The whole NuaDHA® and NuaEPA® range is in re-TG form.

EFSA and the Turkish Food Codex have authorised claims for DHA on brain function and vision. EPA has no authorised health claim on its own. The regulation allows general benefit statements only when they come with an authorised health claim, so we make no benefit statement about NuaEPA®. We describe only its content, form, purity and independent test results.

Results for the NuaDHA® and NuaEPA® lots tested in the IFOS programme are published on the public IFOS results page. You can find the test report for your own lot with the lot number on your box. The three steps to find the report are on the Nua Series page. The NSF Certified for Sport® listing (90-capsule packs) is on the public NSF list of certified products. Both pages are linked from this page. For questions, write to bilgi@longevicals.com.

Studies cited on this page.

The sources reflect the general scientific literature on the nutrient and its forms. They make no claim about clinical results specific to our products.

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Scientific Opinion on the substantiation of health claims related to docosahexaenoic acid (DHA) and maintenance of normal brain function and maintenance of normal vision. EFSA Journal 2010;8(10):1734. https://doi.org/10.2903/j.efsa.2010.1734
Türk Gıda Kodeksi Beslenme ve Sağlık Beyanları Yönetmeliği (Turkish Food Codex Regulation on Nutrition and Health Claims) and its annexed list of health claims (Official Gazette, in Turkish). https://www.resmigazete.gov.tr/
Dyerberg J, Madsen P, Møller JM, Aardestrup I, Schmidt EB. Bioavailability of marine n-3 fatty acid formulations. Prostaglandins Leukot Essent Fatty Acids 2010;83(3):137-41. https://doi.org/10.1016/j.plefa.2010.06.007
Neubronner J, Schuchardt JP, Kressel G, Merkel M, von Schacky C, Hahn A. Enhanced increase of omega-3 index in response to long-term n-3 fatty acid supplementation from triacylglycerides versus ethyl esters. Eur J Clin Nutr 2011;65(2):247-54. https://doi.org/10.1038/ejcn.2010.239
Schuchardt JP, Hahn A. Bioavailability of long-chain omega-3 fatty acids. Prostaglandins Leukot Essent Fatty Acids 2013;89(1):1-8. https://doi.org/10.1016/j.plefa.2013.03.010

The sources reflect the official scientific assessments of the nutrient and the text of the regulation. They make no claim about clinical results specific to our products.

To read more on the topic, our other guides are on the Longevity Analyses page.

*Health claims apply when the nutrient is consumed in sufficient amounts. The information on this page is for education. Food supplements are not medicines and should not be used as a substitute for a varied, balanced diet. The studies listed under Sources reflect the general scientific literature on the nutrient and its forms. They make no claim about clinical results specific to our products. If you are pregnant or breastfeeding, take medication or have a chronic condition, consult your physician before use.