Diabetes in Pets
Novo Semilente MC
Semilente by Novo Nordisk
short-acting Porcine
U40 Zinc
Line Novo
Also known as pork semilente, semilente pork
Similar to  
  • None
Action in cats  
  • onset Xh,
  • peak Xh
  • duration Xh
Action in dogs  
  • onset within 45 minutes,
  • peak 2-4h,
  • duration 4-6h
Use and Handling
Type cloudy
Shelf Life 36 months
When opened 6 weeks room temp.
In pen N/A

This appears to be one of the last "plain" semilente insulins marketed. Novo Nordisk distributes it in Germany, but not in places like the US, Canada and the UK. Semilente insulin has an activity pattern similar to that of R/Neutral.

The MC (stands for Monocomponent) designation seen in the insulin's name means it is of animal origin and highly purified. In some markets, Novo Nordisk "codes" their insulin in this manner: MC is insulin of animal origin, while HM is of r-DNA/GE/GM origin. In the past, the MC designation could mean it was made of beef, of pork, or a blend of both, as it was a way of distinguishing highly purified beef and pork insulins. Seeing it today means the insulin is of pure porcine origin, as Novo discontinued its bovine insulins some time ago.

What Semilente Is Not

No Lente-type insulin regardless of species can contain any NPH/isophane insulin[1] or any R/Neutral insulin[2].

Both are chemically impossible: the phenol preservative present in NPH/isophane alters the action of Lente-type insulins, creating a mixture with an approximate action of R/Neutral[3].

The zinc suspension of Lente-type insulin binds R/Neutral, causing the short-acting insulin to slow, losing its short-acting effect.

Novo Nordisk Semilente MC 40- Porcine (Pork) Insulin-German Packaging. This is semilente pork insulin (Insulin vom Schwein) in U40 strength. Novo has recently discontinued this insulin and Polfa-Tarchomin (Poland) recently began producing a similar insulin.

Combining Lente Family Insulins

None of the Lente family of insulins (semilente, Lente, Ultralente) can be combined with[4] NPH/isophane insulins. The phenol preservatives present in NPH-type insulins alters the Lente-types to the point where they become a close approximation of R/neutral, with regard to action[5].

Keeping the phenol preservatives in mind, all protamine-suspended insulin mixes would be "off limits" regarding same syringe mixing with any Lente-type insulins[6].

Insulin manufacturers[7] indicate that R/neutral and semilente, Lente, ultralente insulins are able to be combined in the same syringe, but only just before injection. In pre-filled syringes, the zinc suspension of the Lente-type insulins binds the R/neutral, causing it to lose its short-acting effect. Various studies have documented this, and some doctors advise against using R/neutral in the same syringe with the Lente family of insulins[8][9][10][11].

Mixing semilente with either NPH/isophane or PZI will alter the semilente insulin because of the phenol preservatives present in either of them.

Novo Nordisk has discontinued this insulin[12]. Polfa-Tachomin of Poland has recently started producing their own brand of pork semilente insulin which should be available in the UK & Europe.